1.1 Introduction to Computer Systems

 

1.1 Introduction to Computer Systems

 

1.1.1 Definition and features of computer system

The word “Computer” comes from the Latin word Computare, which means “to calculate”. A computer is an electronic device that accepts data as input, processes it according to given instructions, stores data and results, and produces meaningful information as output.

Features of a Computer

 

1. Automatic

A computer works automatically once instructions are given through software. Once a program is started, the computer performs tasks automatically without human intervention. Example: Printing 1000 pages continuously without monitoring.

 

2. Speed

A computer system can perform millions of calculations per second. It completes tasks much faster than humans. The table below shows the speed of the computer in different units of time.

Unit of Time	Part of second	Power of 10
Millisecond	1/1000	One Thousand (10-3)
Microsecond	1/1000000	One Millionth (10-6)
Nanosecond	1/1000000000	One Billionth (10-9)
Picosecond	1/1000000000000	One Trillionth (10-12)
Femtosecond	1/1000000000000000	One Quadrillionth (10-15)

 

3. Accuracy

A computer provides accurate results if correct data and instructions are given. Errors occur only due to wrong input or programs. The incorrect output produced due to incorrect input is referred to as Garbage In Garbage Out (GIGO). Errors due to hardware or software faults are called bugs.

 

4. Storage

A computer can store a large amount of data, information, and programs for future use.1 Byte = 1 character.

1 Bit = 1 or 0	4 bits = 1 Nibble
8 bits = 1 Byte	1024 bytes = 1 KB	KB-Kilobyte	EB-Exabyte
1024 KB = 1 MB	1024 MB = 1 GB	MB-Megabyte	ZB-Zettabyte
1024 GB = 1 TB	1024 TB = 1 PB	GB-Gigabyte	YB – Yottabyte
1024 PB = 1 EB	1024 EB = 1 ZB	TB-Terabyte
1024 ZB = 1 YB		PB-Petabyte

 

5. Diligence

A computer can work continuously for a long time without getting tired or losing efficiency. The capability of a computer to perform a task repeatedly without losing speed and accuracy for a long time is known as diligence.

 

6. Versatility

A computer system can perform different types of tasks such as calculations, document creation, internet browsing, and multimedia work. Versatility refers to the capability of doing various kinds of tasks.

 

7. No Intelligence

A computer cannot think or make decisions on its own. It works strictly according to the instructions provided by the user.

 

 

1.1.2 Application Areas of Computer Systems

Computers are very powerful and versatile. They help people work faster, correctly, and more efficiently. With computers, people can prepare documents, spreadsheets, presentations, and graphics. They can also enjoy modern facilities like instant messaging, video chatting, email, online shopping, ticket booking, banking, and getting the latest news. Today, computers are used in almost every field of life. Some important applications are:

 

Education

Computer systems are used in education for teaching and learning purposes. Teachers use computers to prepare teaching materials and presentations, while students use them for learning through the internet, online classes, and educational software. Computers are also used to keep student records and examination results.

 

Communication

Computers play a vital role in communication. They are used to send and receive information through email, video conferencing, chatting, and social media platforms. Computers make communication faster, easier, and global.

 

Entertainment

Computers are used in entertainment for playing games, watching movies, listening to music, animation, and video editing. They provide digital entertainment through multimedia and online platforms.

 

Banking

In the banking sector, computers are used for maintaining customer records, processing transactions, online banking, ATM services, and generating bank statements. Computer systems have increased accuracy, speed, and security in banking services.

 

Medicine and Healthcare

Computer systems are widely used in hospitals and healthcare centers. They are used to maintain patient records, assist in medical diagnosis, operate medical equipment, and manage hospital systems. Computers are also used in medical research.

 

Scientific research

Computers are used in scientific research to analyze large amounts of data, conduct simulations, weather forecasting, and space research. They help scientists perform complex calculations accurately and quickly.

 

Business

In business organizations, computers are used for accounting, billing, payroll processing, inventory management, record keeping, and communication. They help in efficient management and decision making.

 

Agriculture

Computers are used in agriculture for weather forecasting, crop management, data analysis, and modern farming techniques. They help farmers increase productivity and efficiency.

 

Transportation

Computers are used in transportation systems for ticket booking, traffic control, navigation, and managing transport schedules. They help reduce human errors and improve safety.

 

Government Offices

Government offices use computer systems for census data, record keeping, tax systems, e-governance services, and public administration. Computers improve efficiency and transparency in government services.

 

 

1.1.3 Functions of a computer system: Input, Process, Output, Storage (IPOS) with Basic Block Diagram.

 

A computer system performs its work through four basic functions known as the IPOS cycle. IPOS stands for Input, Process, Output, and Storage. These functions work together to convert data into meaningful information.

 

The block diagram of the IPOS cycle of the computer system as:

 

1. Input

Input is the process of entering raw data and instructions into the computer system.
Input devices such as keyboard, mouse, scanner, and microphone are used to provide data to the computer.

 

2. Process

Processing is the operation performed on the input data according to the given instructions.
The CPU (Central Processing Unit) processes data by performing arithmetic and logical operations to convert data into information.

 

3. Output

Output is the result produced after processing the data.
Output devices like monitor, printer, and speaker are used to display or produce the processed information.

 

4. Storage

Storage refers to saving data, programs, and results for future use.
A computer uses primary memory (RAM, ROM) and secondary memory (HDD, SSD, pen drive) to store information.

 

 

1. The word “Computer” is derived from which word? [k]

A. Compute                B. Calculus                 C. Computare ✅                   D. Calculation

2. A computer is best defined as: [k]

A. A mechanical device                      B. An electronic device that processes data ✅
C. A thinking machine                                    D. A communication tool

3. Which feature allows a computer to work without human intervention once started? [k]

A. Speed                     B. Accuracy                C. Automatic ✅                    D. Versatility

4. Performing millions of calculations per second shows which feature? [u]

A. Accuracy                B. Speed ✅               C. Storage                               D. Diligence

5. Wrong output due to wrong input is called: [k]

A. Bug                         B. Virus                       C. GIGO ✅                           D. Malware

6. A computer working continuously for long hours shows: [u]

A. Accuracy                B. Speed                      C. Diligence ✅                     D. Versatility

7. A computer editing videos, calculating results, and browsing the internet shows: [a]

A. Speed                     B. Accuracy                C. Versatility ✅                    D. Storage

8. Which feature proves that a computer cannot think on its own? [k]

A. Speed                     B. Accuracy                C. Automatic                          D. No intelligence ✅

9. Which unit represents one billionth of a second? [k]

A. Microsecond          B. Millisecond            C. Nanosecond ✅                 D. Picosecond

10. Which unit represents one trillionth of a second? [k]

A. Nanosecond           B. Microsecond          C. Picosecond ✅                   D. Femtosecond

11. Sending emails and video calls belongs to: [k]

A. Entertainment        B. Business                 C. Communication ✅           D. Research

12. Online shopping and billing are examples of computer use in: [u]

A. Business ✅          B. Education               C. Agriculture             D. Government

13. Weather forecasting mainly uses computers in: [u]

A. Entertainment        B. Agriculture             C. Communication     D. Scientific research ✅
14. Computers reduce human error most effectively in: [ HA]
A. Entertainment        B. Manual work          C. Automated systems ✅      D. Games

15. IPOS stands for: [K]

A. Input, Program, Output, Storage               B. Input, Process, Output, Storage ✅
C. Instruction, Process, Output, Speed           D. Input, Processing, Object, System

16. Entering data into the computer is called: [K]

A. Processing              B. Output                    C. Input ✅                D. Storage

17. Which device is used for input? [K]

A. Monitor                  B. Printer                    C. Keyboard ✅         D. Speaker

18. Which part processes data in a computer system? [K]

A. Output device        B. CPU ✅                 C. Input device           D. Storage device

19. Arithmetic and logical operations are done by: [U]

A. CU                          B. Register                  C. ALU ✅                 D. ROM

20. The processed result displayed to the user is called: [K]

A. Input                       B. Output ✅              C. Storage                   D. Processing

21. Saving data for future use is called: [K]

A. Input                       B. Processing              C. Output                    D. Storage ✅

22. Which memory is volatile? [U]

A. ROM                      B. HDD                                   C. SSD                        D. RAM ✅

23. Which stage converts data into information? [A]

A. Input                       B. Storage                   C. Processing ✅        D. Output

24. Which statement best explains the term “Garbage In, Garbage Out (GIGO)” in a computer system? [HA]

A. Computer always produces correct output B. Computer can correct wrong input automatically
C. Wrong input leads to wrong output ✅                 D. Computer makes decisions on its own

25. In the basic block diagram of a computer system, which component directly controls and coordinates all operations? [A]

A. Input Unit              B. Output Unit            C. Storage Unit           D. Central Processing Unit (CPU) ✅

 

Short Questions

 

What is computer? Explain why a computer is called an automatic machine.

What is GIGO? How does diligence differentiate a computer from humans?

What is versatility? Explain accuracy as a feature of a computer system.

Why is a computer said to have no intelligence?

Explain the importance of storage in a computer system.

How do computers help farmers in agriculture?

Explain the use of computers in business organizations.

 

Long Questions

 

Draw and Explain the functions of a computer system with reference to the IPOS cycle.

Define a computer system and Explain any five features of a computer system.

Explain the application of computer systems in different fields.

Describe the role of computers in education and communication.

Explain the use of computers in banking and healthcare sectors.

Explain how computers are useful in business and government offices.