Friday, August 9, 2024

(1.1) Networking & Telecommunications

 

1. Introduction Technology Fundamentals

(1.1) Networking & Telecommunications

 

Communication

The process of sending and receiving data and information between two or more than two people is known as communication.

 

Telecommunication

The transmission of data and information from one place to another for the purpose of communication is known as telecommunication. E.g. mobile phone, Internet phone, television, landline, radio, etc.

 

Data communication

Data communication is the process of transferring data and information between computers and other electronic devices. E.g.  E-Mail, Chat and phone calls

 

Components of Data Communication

 

The basic elements of data communication are: data (message), sender, medium, receiver and protocol.

 

Data (message) : Data is to be communicated between sender and receiver.

Sender : Sender is a device used to transfer data.

Medium: Medium is a channel through which sender and receiver make communication.

Receiver: Receiver is a device used to receive data.

Protocol: Protocol is a set of rules followed by sender and receiver.

 

Data Transmission Mode

Data transmission mode is the way of transmission of data from one location to another.

There are three types of transmission mode:
i) Simplex mode        

ii) Duplex mode         

 

Simplex mode
Simplex mode is the transmission of data and information that takes place in only one direction. It is a unidirectional mode of data transmission.

Radio, newspaper, television broadcasting, books etc. are examples of simplex mode.

 

Duplex Mode

Duplex is mode of data transmission in which data and information flow in both directions. It is bi-directional mode of data transmission. The two types of duplex modes are:

i) Half Duplex Mode

ii) Full Duplex Mode

 

Half duplex mode
Half-duplex is the transmission of data and information that flows in both directions but only one direction at a time. Walky-talky and wireless handset are examples of half-duplex mode.

 

Full duplex mode

Full duplex mode is the transmission of data and information that flows in both direction simultaneously on the transmission path. Mobile and landline phones are examples of full duplex mode.

 

 

Simplex Mode

Full Duplex Mode

Simplex mode is the transmission of data and information that takes place in only one direction.

Full duplex mode is the transmission of data and information that takes place in both directions simultaneously on the transmission path.

It is a unidirectional mode of data transmission.

It is bi-directional mode of data transmission

Radio, newspaper, television broadcasting, books etc. are examples of simplex mode.

Mobile and landline phones are examples of full duplex mode.

 

 

Simplex Mode

Half Duplex Mode

Simplex mode is the transmission of data and information that takes place in only one direction.

Half duplex mode is the transmission of data and information that takes place in both directions but only one direction at a time. .

It is a unidirectional mode of data transmission.

It is bi-directional mode of data transmission

Radio, newspaper, television broadcasting, books etc. are examples of simplex mode.

Walky-talky and wireless handset are examples of half duplex mode.

 

Communication Media / Transmission Media

A channel or path through which data and information are transmitted between connected devices in a network environment is called communication media.

The two main types of communication media are:

1. Guided (Wired/bounded) communication media

2. Unguided (Wireless/unbounded) communication media

 

1. Guided (Wired/bounded) Communication Media

The media which uses cable or wire to transfer data and information among computers are called guided communication media.

This is an easy, fast and secure way to transfer data and information from one computer to another.

 

The three types of wire or cable are:

a. Twisted pair Wire

b. Co-Axial Cable

c. Fiber Optic Cable

 

Twisted Pair Wire

Twisted pair wire is made of copper and a pair of wires are twisted together and insulated with plastic.

This is also widely used in landline telephone.

RJ-45 connector is the most popular connector used in twisted-pair wire.

Wires are twisted with each other so as to reduce crosstalk (A disturbance caused by electromagnetic interference, along a circuit or a cable pair).

 

The two types of twisted pair wire are:

i. UTP (Unshielded Twisted Pair)      ii. STP (Shielded Twisted Pair)

 

Unshielded twisted pair (UTP)

Unshielded twisted pair is a popular type of cable that consists of two unshielded wires twisted around each other which are used in telephone wiring and local area networks (LANs). 

It is called unshielded because it has no additional foil wrap, or shield.

RJ-45 connector is commonly used with unshielded twisted pair.

Shielded twisted pair (STP)

Shielded twisted pair is a type of copper telephone wiring in which each of the two copper wires are twisted together and coated with an insulating coating.

The extra covering in shielded twisted pair wiring protects the transmission line from electromagnetic interferenceD-shell connectors are used with shielded twisted pair.

 

UTP (Unshielded Twisted Pair)

STP (Shielded Twisted Pair)

UTP cable is a twisted pair cable with wires that are twisted together. Transferring speed of the data signal is slow

It is enclosed within a foil or mesh shield. Transferring speed of the data signal is high

In UTP, the electromagnetic interference is more than the STP while transferring the signal to the transmission media.

It reduces electromagnetic interference while transferring the signal to the transmission media.

 

Co-axial cable

Coaxial (or “coax”) cable is a common type of cable used for transmitting data over long distances.

They are most commonly used to transmit cable TV and Internet signals.

BNC and T connectors are the most popular connector used in co-axial cable.

 

Fiber optic cable

Fiber optics cable is one of the costlier cables used in data communication which uses light to carry a data signal through the cable.

The connectors used in fiber optics are Screw Mounted Adaptors (SMA), Straight Tip Connector (ST), SC and FC (Ferrule Connector).

 

2. Unguided (Wireless/unbounded) Communication Media

Unguided communication is a communication channel in which data and information transferred between two devices without using wire or cable.

It uses radio signal for receiving and transmitting electronic data.

 

The three types of wireless communication are:

l Radio Wave

l Micro Wave

 l Satellite Communication

 

Radio wave transmission

The transmission making use of radio waves through air is called radio wave transmission.

It provides low bandwidth for data communication.

Radio, TV, cellular phones etc. uses radio transmission in one form or another.

The radio waves can travel through walls and through an entire building.

Depending upon the frequency, they can travel long distance or short distance.

It does not require line of sight for data transmission

 

Microwave transmission

Microwave is a line-of-sight wireless communication technology that uses high frequency beams of radio waves to provide high speed wireless connections that can send and receive voice, video, and data information.

Microwaves do not pass through buildings. So, indoor receivers cannot be used effectively.

It provides higher bandwidth for data communication.

It requires line of sight for data transmission.

 

 

Radio wave Transmission

Microwave Transmission

The transmission making use of radio waves through air is called radio wave transmission.

Microwave is a line-of-sight wireless communication technology that uses high frequency beams of radio waves.

The radio waves can travel through walls and through an entire building.

Microwaves do not pass through buildings. So, indoor receivers cannot be used effectively.

It provides low bandwidth for data communication.

It provides higher bandwidth for data communication.

It does not require line of sight for data transmission

It requires line of sight for data transmission.

 

Infrared transmission

Infrared Transmission is the transmission of data or voice information over infrared (IR) light over short ranges.

It requires line-of-sight and is unable to break through walls.

 

Satellite Communication

Satellite communication is used to transfer information wirelessly worldwide after 1965.

It is an artificial satellite placed in outer space for the purpose of telecommunication, radio, television, Internet, etc. Text, photo, video, etc. can be transferred worldwide using satellite communication.

It is like microwave relay stations in the space or sky.

 

Guided Media

Unguided Media

The media which uses cable or wire to transfer data and information among computers are called guided communication media.

Unguided communication is a communication channel in which data and information are transferred between two devices without using wire or cable.

Guided media is used for point-to-point communication.

Unguided media is generally suited for radio broadcasting in all directions.

Capable of high-speed data transmission.

Slower data transmission compared to guided media.

Examples of guided media are Twisted Pair Cable, Co-Axial Cable and Fiber Optic Cable

Examples of unguided media are Radio Wave, Micor Wave and Satellite Communication

 

Computer Network

Computer network is a group of two or more computers and devices connected to each other through wired or wireless media to exchange data and information and share hardware, software and other resources.

It can share resources like scanner, printer, hard disk, operating system software, application software, etc. within the networking computer.

The services provided by computer network are print service, message service, application service, file service, database service, etc.

 

Advantage of Computer Network

1. A network connected computers can share hardware devices such as scanner, printer, hard disk, etc.

2. It can communicate and share information all over the world through Internet.

3. Computer network supports centralized administration.

4. Networking also provides the facility of data and software backup system.

 

Disadvantage of Computer Network

1. Computer network can be route for computer virus and malware transmission.

2. Skilled manpower is required to manage and operate computer network.

3. The initial setup cost is very high to build computer network.

4. Cybercrimes are originated from computer network.

 

"Computer network reduces the operation cost." Justify this statement.

Computer network reduces the operation cost as it allows to share software and hardware in the network, so extra hardware or software copies is not needed to install for each and every computer in the network.

 

Basic Elements of the Network

·       Physical parts and devices used to connect computers in the network environment are called hardware components.

·       The hardware components of computer network are computer set, modem, hub, NIC card, bridge, repeater, etc.

·       The software elements are NOS, Protocol and Device Driver

 

1. NIC Card

NIC stands for Network Interface Card which connects all computers in network.

It provides a port on the back of system unit to connect a computer in network.

It controls flow of data to and from computers in network environment.

 

2. Connectors

Connectors are used to connect communication media with network devices.

It provides data communication through NIC card.

 

The different types of connectors are:

 l RJ- 45 connector for UTP cable

l BNC connector for co-axial cable

l ST connector for fiber optics cable

 

3. Hub

Hub is a network connectivity device with multiple ports for connecting different computers on network.

It connects computers in star topology.

It broadcasts all network data across each connection.

 

4. Switch

Switch is a network connectivity device which joins multiple computers together to share information among them.

The selected computer can get information through switch.

It works faster than hub.

 

Hub Vs Switch

Hub

Switch

It is cheaper than switch.

It is more expensive than hub.

It transmits data slower than switch.

It transmits data faster than hub.

It broadcasts the information packets to all computer connected network.

It transfers packets to only those selected computers connected in network.

It has 4 / 12 ports

It has 24 to 48 ports

 

5. Bridge

Bridge is a network connectivity device that interconnects two computer networks having similar protocol.

It inspects incoming signals and decides whether to forward or discard it.

It connects similar networks.

 

 

6. Router

Router is a network connectivity device that joins multiple wired or wireless networks together.

Like a bridge, router also inspects and forwards data among different networks having similar protocol.

It is an intelligent device that has ability to determine the best possible path for data transmission.

 

Router

Switch

The main objective of router is to connect various networks simultaneously.

The main objective of switch is to connect various devices simultaneously.

Router is used by LAN as well as MAN.

Switch is used by only LAN.

Router is a relatively much more expensive device than switch.

Switch is an expensive device than hub. but cheaper than router.

A router can take a routing decision much faster than a switch.

The switch takes more time while making complicated routing decisions.

 

7. Gateway

Gateway is a network connectivity device that interconnects two networks having dissimilar communication protocols. It is also called protocol converters.

 

8. Repeater

Repeater is a network connectivity device that accepts weak signals and regenerates them and after that sends the message on their way.

It makes possible for long-distance data transfer. So it boosts the data signals that are received from network.

 

9. MODEM (Modulator and Demodulator)

MODEM is a device which connects computers to ISP (Internet Service Provider) by the help of telephone line or router device.

The MODEM which is placed inside the CPU Casing is called internal modem. MODEM which is placed outside the Casing is called an external modem.

 

Importance of MODEM

MODEM converts analog signal to digital signal and vice - versa.  The MODEM converts the computer's digital signals into analog signals which are then transmitted across the phone line which is called modulation phase and The MODEM receives analog signals from phone line and converts into digital signals for the computer which is called demodulation phase.

 

Modulation

The process of translating digital signals of a computer to analog signals, which are then transmitted across the standard telephone lines, is known as modulation.

 

Demodulation

The process of translating analog signals from a phone line and converts then into digital signals for the computer is known as demodulation.

 

Bandwidth

The amount of data that can be carried from one point to another in a given time period is called bandwidth.

We can measure bandwidth in digital devices by bits per second (bps) and in analogue devices by cycles per second (cps) or Hertz (Hz).

 

Network Operating System (NOS)

Network operating system is an important software which controls and manages computer network.

Novell Netware is a popular NOS. Windows NT, Windows XP, Linux, Banyan Vinex, etc. are other example of NOS.

The main functions of NOS are:

l It helps to setup and install network.

 l It allows administration to add or remove users from computer network.

 l It enables users to have access to network resources.

l It manages and controls all the resources of computer network.

 

Protocol

A set of rules followed for interconnection and communication between computers in a network is called a protocol. So it is rules followed while sending and receiving information using network software.

NCP (Network Control Protocol) was the first protocol.

 

Some common protocols are as follows:

l TCP/IP (Transmission Control Protocol/Internet Protocol) is used in Internet.

l HTTP (Hypertext Transfer Protocol) is used to transfer HTML documents in WWW.

l SMTP (Simple Mail Transfer Protocol) is used in sending e-mail.

l POP (Post Office Protocol) is used to retrieve e-mail from a mail server.

 l FTP (File Transfer Protocol) is used to transmitting files between computers.

 

Device driver

Device driver is a program that controls the functionality of the hardware device.

 

Types of Network

Computer network can be classified according to its area covered.

The main three types of computer network on the basis of geographical location (area covered) are:

1. LAN (Local Area Network)

2. MAN (Metropolitan Area Network)

3. WAN (Wide Area Network)

 

1. LAN (Local Area Network)

Local Area Network is a network limited within a small area like a room, a building, school, college, etc. generally connected through wire media.

It can cover up to one kilometre for transferring data and information between the computers.

It has high speed data transfer capacity than MAN and WAN.

Computer in LAN can be connected through wireless media and is referred to as WLAN.

Computer lab networking and cyber networking are examples of LAN.

 

Features of LAN (Local Area Network)

Coverage area is a generally small geographical area such as room, building and few kilometers.

l LAN runs the multiple devices to share a transmission medium.

l The different topology used mainly bus and ring in LAN

l The communication quality is better in LAN, the transmission error rate are low as compare to WAN

LAN supports a variety of communications transmission medium such as an Ethernet cable (thin cable, thick cable, and twisted pair), fiber and wireless transmission.

 

2. MAN (Metropolitan Area Network)

Metropolitan Area Network (MAN) is a network within the area like valley, city, metropolitan, etc. connected through wire or wireless technology or media.

It covers more area than LAN and less area than WAN.

It has high speed data transfer capacity than WAN and is slower than LAN.

It is used in medium size organization having various branches within city or valley.

Cable TV network and telephone networks providing high-speed DSL lines are examples of MAN.

Features of MAN (Metropolitan Area Network)

l Network size up to 50 km. It may be as small as a group of buildings in a campus to as large as covering the whole city.

l It is normally owned by single or multiple organizations.

l It facilitates sharing of regional resources.

l They provide uplinks for connecting LANs to WANs and Internet.

 

3. WAN (Wide Area Network)

Wide Area Network is a network that is extended to a large area i.e. world in which computers are connected through wireless technology or media as satellite communication. It is the largest computer network.

 Internet, 4G Mobile Broadband Systems and satellite communication are the best examples of WAN.

 

Features of WAN (Wide Area Network)

l It covers the whole world and cannot be restricted to any geographical location. It uses satellite and microwave communication.

l It is normally owned by multiple organizations.

 l Communication links are provided by public carriers like telephone networks, satellites, network providers, cable systems, etc.

l They have low data transfer rate and high propagation delay so they have low communication speed.

 

LAN

WAN

Local Area Network is a network limited within a small area like a room, a building, school, college, etc. generally connected through wire media.

Wide Area Network is a network that is extended to a large area i.e. whole world in which computers are connected through wireless technology or media as satellite communication

The speed of LAN is high(more than WAN).

The speed of WAN is slower than LAN.

LAN is owned, managed, and used by an individual or an organization. Therefore, it is a private network.

WAN can be either private or public. The Internet is the best example of public WAN.

The maintenance cost of LAN is easy.

The maintenance cost of WAN is difficult.

 

 

LAN

MAN

Local Area Network is a network limited within a small area like a room, a building, school, college, etc. generally connected through wire media.

Metropolitan Area Network (MAN) is a network within the area like valley, city, metropolitan, etc. connected through wire or wireless technology or media.

The speed of LAN is high(more than MAN).

The speed of MAN is average.

LAN’s ownership is private.

MAN’s ownership can be private or public.

LAN can use twisted pair, coaxial cable, and fiber optic cable for transmission.

MAN usually rely on fiber optic cables.

 

Network Architecture/Model

Network architecture defines how the computer communicates and interacts with each other on network.

 

The three types of network architecture are:

1. Peer to Peer Network

2. Client-Server Network

3. Centralized Network

 

 

1. Peer to Peer Network

Peer to peer is a type of network model where all nodes on the network have an equal relationship with each other. It can share data, hardware and software with each other.

It is suitable for a small area such as small offices, small room, building, etc.

It uses many operating systems such as Windows 2000, Windows 8, Macintosh Operating System etc., have built-in features to support peer to peer network.

 

Advantage of Peer to Peer Network

l All resources and contentions can be shared in this network.

l System administrator is not required and each user can control their shared resources.

l The failure of one computer doesn't affect the functioning of other peers.

 

Disadvantages of Peer to Peer Network

l It is difficult for administrator and control as resources are decentralized in this network.

l Security is very low in this system.

l Data recovery or backup is very difficult.

 

2. Client-Server Network

The network model where one or more powerful computers (servers) provide the different network services and all other users of computer network (clients) access those services to perform user's tasks is known as client-server network. In such networks, there exists a central controller called server.

A server is a specialized computer that controls the network resource and provides services to other computers in the network. Novell Netware, Windows NT, Linux, etc. are the common examples of an operating system of client-server network.

 

Advantages of Client-Server Network

l Centralized back up is possible in client-server computer network.

l The use of dedicated servers also increases the speed of sharing resources.

l Security is better in this network as all the shared resources are centrally administered.

 

Disadvantages of Client-Server Network

l It requires specialized servers with large memory. This leads to an increase in the cost.

l The cost of network operating system that manages the various clients is also high.

l It requires network administrator.

 

3. Centralized Network

A centralized network is a network model in which a central host computer performs data processing and storage on behalf of clients.

·       The main computer is known as host or server computer.

·       Workstation is just used for input/output operations, which has no processing capabilities and are connected to server or host computer. Linux or UNIX operating system is used in centralized network.

 

Advantages of Centralized Network

l It saves cost of installation of network system.

l It secures all data and information on host computer which works on IPOS (input process output system).

l Host Computer gives facilities like Disk storage and software to workstation.

 

Disadvantages of Centralized Network

l The malfunctioning of host computer affects other workstation.

l It takes long time for data processing.

l It is difficult to add more workstation

Client-Server Network

Peer to Peer Network

A network model where one or more powerful computers (servers) provide the different network services and all other users of computer network (clients) access those services to perform user's tasks is known as client-server network.

A network model where all nodes on the network have an equal relationship with each other is known as peer to peer network.

Client-Server Network are costlier than Peer-to-Peer Network.

Peer-to-Peer Network are less costlier than Client-Server Network

Client-Server Network focuses on information sharing.

Peer-to-Peer Network focuses on connectivity.

Client-Server Network is used for both small and large networks.

Peer-to-Peer Network is generally suited for small networks

 

Workstation
A computer on a network that uses resources of the network is called workstation.

 

Node
Each computer or device of network is called node.

 

Network Topology  (LAN Topology)

Network topology is the inter-connected pattern of network components.

A LAN Topology is cabling structure or pattern of computers in local area.

 

The three main types of topology are:

1. Bus Topology

2. Ring Topology

3. Star Topology

 

1. Bus Topology

The type of topology in which all nodes and network devices are connected to single cable is called bus topology. Terminators are attached at the cable's start and end points.

When it has exactly two end points, it is called linear bus topology.

 

Advantages of Bus Topology

l It is cost effective and cable required is least compared to other network topology.

l It is used in small networks and easy to understand.

l It is easy to expand networks.

 

Disadvantage of Bus Topology

l Break/Failure in main cable will make the whole network to malfunction.

l Heavy network traffic or increase in nodes will degrade performance of network.

l Terminators are necessary at both ends of the cable.

 

 

 

 

 

 

 

 

2. Ring/Loop Topology

The type of topology in which each computer is connected to another computer with the last one connected to the first is called ring topology.

It uses fiber optic cable to transfer data.

Each and every computer has equal responsibilities.

Data is transferred in a sequential manner.

 

Advantages of Ring Topology

l In this topology all computers, in close loop, act as a client or server to transfer the information.

l Transmitting network is not affected by high traffic or by adding more nodes.

 l It is cheap to install or setup and expand.

 

Disadvantages of Ring Topology

l It is difficult for troubleshooting.

l In ring topology, adding or deleting the computers disturbs the network activity.

l Failure of one computer disturbs the whole network in this topology.

 

3. Star Topology

The type of topology which connects all nodes to central device called hub/switch through a cable is called star topology.

It is probably the most common topology.

Star topology can be used with twisted pair, optical fiber and coaxial cable.

 

Advantages of Star Topology

l It provides fast performance and low network traffic.

 l It is easy to troubleshoot setup and modify.

 l The failure of one node has not affected the rest of the nodes.

 

Disadvantages of Star Topology

l Hub and more wires are required, so the cost of installation is high.

l The whole network is stopped when the hub fails.

l The system crucially depends on control device switch/hub. If it fails, entire network fails.

 

 

Internet

The worldwide connection of computer networks that use TCP/IP protocols to communicate with one another using wire or wireless media as well as network devices is called the Internet.

Internet is a network of networks.

 

History of Internet

Internet was originated in 1969 AD by ARPANET (Advanced Research Project Agency Network).

ARPANET provides communication among various bodies of government which was developed by United States Department of Defense.

In 1992 AD, the Internet was openly used throughout the world.

In Nepal, Internet service was started by Mercantile Company in 1994 AD.

 

Advantages of internet

a)     Internet has an endless knowledge supply which anyone can access that too free of cost.

b)     Selling and buying has become so easy with the use of internet and it has helped millions to sell and buy their goods online.

c)     Internet has given us E-Mail which is fast, secure and reliable mode of communication.

d)     It makes easy to transfer the file or information.

 

Disadvantages of internet

a)     Increasing virus threats not only steals your sensitive data but also damages your computer.

b)     People using too much of internet get disconnected from the real world. 

c)     Pornography that can get in the hands of young children too easily.

d)     Addiction to online games affects health leading to obesity and serious health issues.

 

 Two major uses of internet

Any two major uses of internet are:

- The internet is used for sending and receiving emails, instant messaging, video calls, and more.

- The internet is a vast source of information and provides access to a wealth of knowledge and data.

 

Extranet

An extranet is a private network that uses internet technology and the public telecommunication system to connect more than one organization.

 Intranet

An intranet is a private computer network that uses the internet protocol to securely share any part of information of an organization.

 

Services of Internet

1. World Wide Web

2. E-mail

3. Telnet

4. FTP (File Transfer Protocol)

5. Search Engine

6. IRC (Internet Relay Chat)

7. Online Banking

8. E-commerce

 

1. World Wide Web

World Wide Web was developed by Tim-Berners-Lee in 1989 AD. It is also called the web.

The interlinked collection of hypertext documents and multimedia content available on internet is called WWW.

 

2. E-mail (Electronic Mail)

E-mail is the most widely used service on the Internet which sends and receives messages electronically through the Internet.

 

E-mail address: Each e-mail address is identified by a unique name. For example sarthak1@gmail.com.

It has four parts they are as follows:

l sarthak1 : User’s name

l @ (At the rate): A separator symbol

l gmail : domain name

l .com, .edu or .net : "commercial" "organization" or "network"

 

Advantages of using E-mail

l It is the cheapest and fastest means of communication.

l It is more reliable than postal mail.

l E-mail can be accessed from any part of the world at any time.

l Information can be shared globally.

l We can send photos, songs, video clips and other file with e-mail attachments.

l A single mail can be sent to multiple people at a time.

 

Disadvantages of e-mail

·        The recipient needs access to the internet to receive email.

·        Viruses are easily spread through email attachments.

·        Minor mistakes in e-mail address may deliver the mail to wrong address.

·        Since it passes through a vast electronic network, it may be seized in between.

 

Any four sites that provide e-mail services are:

a)     www.yahoomail.com

b)     www.hotmail.com

c)     www.gmail.com

d)     www.outlook.com

 

Any two advantage of E-mail over traditional mail.

Any two advantage of E-mail over traditional mail

v Emails can be sent and received almost instantly, allowing for quick communication and faster decision making. Traditional mail, on the other hand, can take several days to arrive.

v Emails can be sent from anywhere with an internet connection, and they can be easily organized and stored for future reference. Traditional mail requires physical transportation, which can be inconvenient and time-consuming.

 

3. Telnet

Telnet is the facility of Internet that allows user to use a remote computer through Internet.

 

4. FTP (File Transfer Protocol)

File Transfer Protocol (FTP) is transmission of files between computers on the Internet.

File Transfer protocol helps to transfer (download or upload) files from one computer to another computer.

 

Uploading

Uploading refers to the process of sending or transferring data (files, documents, images, videos, etc.) from a local device, such as a computer or smartphone, to a remote server or another device.

 

Downloading

Downloading is the process of receiving or retrieving data (files, documents, images, videos, etc.) from a remote server or another device to a local device.

 

5. Search Engine

Search engine is the communication program that searches documents on the basis of specified keywords and returns a list of the web links that matches the keywords.

Google, Ask, Alta Vista, Bing and Yahoo can search for files on WWW (World Wide Web).

 

6. IRC (Internet Relay Chat)

IRC allows people from all over the world to communicate in real-time. Real-time communication means communicating with people in the immediate present time.

 

7. Online Banking

Online banking is also known as Internet banking or web banking which allows a user to conduct financial transactions through Internet.

It offers customers almost every service traditionally available through a local branch including deposits, transfers, and online bill payments.

Online banking is fast and efficient. Convenience is a major advantage of online banking.

 

8. E-commerce

E-commerce is also known as electronic commerce or Internet commerce which means buying and selling of goods, products, or services through Internet.

Transaction of money, funds, and data are also considered as E-commerce.

Online stores like hamrobazar, alibaba, muncha, foodmandu, Amazon, Flipkart, Shopify, Myntra, Ebay, Quikr, Olx, etc. are examples of E-commerce websites.

 

ISP (Internet Service Provider) 
An Internet service provider (ISP) is an organization that provides services for accessing and using the Internet.
World Link, Mercantile, Classitech, Vianet etc are the ISPs of Nepal.

Web browser

Web browser is a computer program that access web pages and displays them on the user’s computer.

E.g.,  Mozilla Firefox, Google Chrome, Internet Explorer, opera etc.

 

Video Conference

Video conference is a live two way transmission of audio and video signals between specialized devices or computers at two or more locations via satellite over a network.

 

Internet Telephony

Internet telephony is the science or technology of integrating telephone services into computer networks.

 

Newsgroup

Newsgroup is an online discussion through electronic bulletin board system and chat system. The Usenet is a huge worldwide collection of discussion groups.

 

Social media

Social media  is the internet based electronic communication through which users create online communities to share information, ideas, personal messages and other content such as documents, videos and photos through Internet. Eg, Facebook, twitter, WhatsApp, Instagram etc.

 

Analog signal

An analog signal refers to a continuous electrical signal that varies over time and represents data as a continuous waveform

 

Mail server

A mail server is a computer system that is dedicated to handling and managing the sending, receiving, and storage of emails.

 

Web server

A web server is a software or hardware that delivers web content to clients like browsers.

 

E-mail address

An email address is a unique identifier used for sending and receiving electronic messages over the internet

 

IP address.

IP address is an unique numerical identifier for every device or network that connects to the internet.

 

Why switch is also known as smart hub?

Switch is also known as smart hub  because it transfers packets to only those selected computers connected in network.

 

Where does intranet has been used?

Intranet has been used to share internal information and resources within an organization. 

 

30. Differentiate between internet, intranet and extranet.

 

Extranet

Internet

Intranet

Private network for external parties

Global public network

Private network within an organization

Controlled access for specific external users

Public access for anyone

Restricted access for internal employees

 


 

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