What is Computer and its types

Updated: Aug 2

What is a computer and different types of computers?

Computers are multipurpose electronic devices that store, process, transmit, and receive data. A computer can take data, such as numbers, text, images, etc. The computer takes the input data and processes them to create useful information. A computer can store data and information for future reference also. A computer can also perform scheduled tasks. Computers can be programmed. Computer programmers create programs and software that take input, process it, and output information.

A computer has four components: the CPU (central processing unit), primary memory, input and output, and primary memory. The system bus links all four elements and allows information to be passed and relayed between them. This architecture and type of computer organisation are known as a "von Neumann Machine" in honour of John von Neumann, who designed the first digital computer.

Computers Classified by Size

  1. Supercomputers

  2. Mainframe computers

  3. Minicomputers

  4. Personal computers (PCs) or microcomputers

1. What is Supercomputer?

Supercomputers are the largest and fastest computers. These computers are capable of processing vast amounts of data. A supercomputer can process trillions upon trillions of instructions in one, and it is interconnected with thousands of processors.

Supercomputers are used in engineering and scientific applications, such as weather forecasting and nuclear energy research. In 1976, Roger Cray developed the first Supercomputer.

Supercomputer characteristics and applications:

  • It can decrypt your password for enhanced security.

  • It can produce excellent animations.

  • It's used to simulate nuclear weapons testing and for critical medical testing.

  • It can forecast and analyze weather conditions and study climate patterns. It can be run by NOAA (National Oceanic and Atmospheric Administration), which can execute simple and logical data.

  • It assists in the design of flight simulators for beginner pilots to help them train.

  • It extracts valuable information from cloud systems or data storage centres. It is used, for example, by insurance companies.

  • It was essential in managing online currencies such as bitcoin and the stock market.

  • It aids in diagnosing various critical diseases and producing accurate results for brain injuries, strokes, and other related conditions.

  • It aids in scientific research by analysing the data from satellites and exploring the solar system.

  • It also predicts the levels of pollutants and fog in the atmosphere.

2. What is Mainframe computer?

Mainframe computers can support thousands or hundreds of users simultaneously and run multiple programs simultaneously, which means they can run various processes simultaneously. This makes mainframe computers ideal for large organisations such as banks and telecoms that need to process large amounts of data.

Mainframe computers can support thousands or hundreds of users and run multiple programs simultaneously; this means they can simultaneously execute various processes. This makes mainframe computers ideal for large organisations such as banks and telecoms sectors that need to process large amounts of data and require integer operations like indexing, comparisons, etc.

Mainframe Computer Characteristics:

  • It can process large amounts of data, such as. It can process millions of transactions per second in the banking industry.

  • It is very durable. After proper installation, it can continue to run for as long as 50 years.

  • It provides excellent performance and large-scale memory management.

  • It can share its workload with other processors or input/output terminals.

  • Processing in mainframe computers is much more reliable and less likely to be hampered by bugs or errors. It is possible to correct any errors that occur without affecting performance quickly.

  • It can protect stored data as well as any ongoing information exchange.

Mainframe Computer Applications:

Health Care: It allowed hospitals to record their millions of patients to contact them regarding treatment, medication updates, or other matters related to their appointment.

It allows defense departments to share sensitive information with other military branches.

Large universities use it in education to store, retrieve and manage data related to admissions, students and teachers, and employees from affiliated schools and colleges.

The retail industry has large customer bases and branches using mainframe computers to manage and execute huge transactions quickly.

3. What is Minicomputer?

It is a medium-sized multiprocessing computer. It can host up to 200 users. Mainframe computers can be found in departments and institutes for inventory management, billing, and accounting tasks. The minicomputer is located between the mainframe computer and the microcomputer. It is smaller than the mainframe but more potent than a microcomputer.

Mainframe and minicomputer characteristics:

● Its light weight makes it easy to transport and fit anywhere.

● It is cheaper than mainframe computers.

● It is swift for its size.

● It is still charged for an extended period.

● It doesn't require a controlled operating environment.

Minicomputer Applications:

Minicomputers are primarily used for three main functions:

Process control was used in process control for manufacturing. It has two main parts: it collects data and provides feedback. The minicomputer detects any anomalies in the process and makes the necessary adjustments.

Data management - This is an excellent tool for small businesses to store, share and collect data. Local hospitals and hotels can use it to keep records of patients and customers.

Communications Portal - It can also serve as a communication device within larger systems, as a gateway between a human operator and a central processor/computer.

4. What is Microcomputer?

The name personal computer is also known as a microcomputer. This computer is intended for personal use and is general-purpose. It includes a microprocessor that acts as a central processing unit, memory storage area, input and output units, and microprocessor. Microcomputers can be found on desktop and laptop computers. These computers are ideal for personal tasks such as watching movies or doing assignments.

Characteristics for a microcomputer:
  • It is the smallest of all computer types.

  • Only a limited number of software is allowed to be used.

  • It can be used for personal and professional work. One user can use the program at a given time.

  • It is smaller and easier to use.

  • It doesn't require any special skills or training.

  • It usually comes with a single semiconductor chip.

  • Multitasking is possible with this device, including printing, scanning, browsing and watching videos.

Mains Parts of Computer

1. CPU

Because programs are executed here, computer scientists refer to the CPU as the computer's brain. A program is a collection of instructions instructing the computer to perform a particular task. This could include opening a browser, sending a file to a printer, or playing music and video.

The CPU can be further broken down into three components:

  • The arithmetic units handle all simple mathematical computations.

  • The control units interpret instructions in computer programs.

  • The instruction decoding un converts computer programming instructions to machine code.

All components of a computer can understand machine code.

2. Memory

After converting a set of computer program instructions to machine code, the CPU stores that machine code in primary storage or memory. Machine code can be treated either as data or instructions. The CPU retrieves data and instructions from memory and uses the instruction to manipulate them. Finally, it sends the result back to memory with the next set.

3. Input Units

All input units are devices you use to transmit information to your computer. These include a keyboard, hard drive, or networking card. In essence, these devices bring data from the "outside" to your computers, like your eyes and ears get information into your brain. Each input device comes with its hardware controller, which connects to the CPU's primary memory and provides instructions to the CPU on how to use it.

4. Output Units

Output units are devices your computer uses to communicate information, such as printers, monitors, and speakers. Everything you see on your computer's monitor is machine code stored in memory, and the CPU converts that machine code into the format required by your monitor's display hardware. The monitor's hardware converts this information into different light intensities to allow you to see pictures or words.

What are Personal Computers?

Personal computer (PC) - A small computer that one user can use at a given time.

A microcomputer or PC uses one chip (microprocessor) for its central processing unit (CPU).

Although "microcomputer" refers primarily to a computer, it can also refer to small computers such as tablets, smartphones, or desktop computers.

Different types of Personal Computers:

1. Desktop

A computer that can be placed on top of a desk. Usually, the monitor is on top. Tower model computers are taller and narrower than desktop models. Desktop model computers have three internal mass storage devices due to their form. Sometimes, desktop models that are very small and compact are called slimline.

2. Notebook computer

A very lightweight personal computer. Notebook computers are typically less than 6 pounds and small enough to carry around in a briefcase. The display screen makes a notebook computer different from a personal computer. Flat-panel technologies are a method of creating lightweight, non-bulky display screens for notebook computers. Many factors affect the quality of notebook display screens. Modern notebook computers have a computing power almost equal to personal computers. They share the same CPUs, memory capacities, and disk drives. All this power is in a small package and can be expensive. Notebook computers are twice as expensive as regular-sized computers. Notebook computers are equipped with battery packs that allow you to use them without having to plug them in. The batteries must be charged every few hours.

3. Laptop computer

A portable, miniature computer that can be placed on your lap. Laptop computers are often referred to as notebook computers.


4. PDA

A personal digital assistant is a handheld device that integrates computing, phone/fax and networking. A typical PDA functions as a cellular phone and fax sender. It can also be used as an organiser. PDAs, unlike portable computers, are pen-based. They use a stylus to input data rather than a keyboard. They also include handwriting recognition features. Some PDAs are capable of responding to voice input using voice recognition technology. Apple Computer introduced the Newton MessagePad in 1993, a pioneering product in the field of PDA. Several other manufacturers soon followed Apple's lead and introduced similar products. PDAs have not had much success on the market due to their high prices and limited uses. Many experts believe that PDAs are going to become an everyday gadget.

PDAs can also be called pocket computers, palmtops and handheld computers.

According to technology there are types of computers.

1. Analog computer

2. Digital computer

3. Hybrid computer

1. Analog Computer: Analog computer handles or process information of a physical nature like temperature, pressure etc.

2. Digital Computer:

Digital computer process information which is essentially in a two state form is called the binary. It has two numbers zero and one. There are different types of digital computers like microcomputers, minicomputers, mainframes and supercomputers.

3. Hybrid Computer: Hybrid computer are those computer which has some element of analog computer and some of digital computer. i.e. we can say that hybrid computer has both types property analog and digital computers.

Characteristics of Computers:

There are following characteristic of computers which are below:


It can perform any type of work with high speed comparison as a person. It takes few time for any type of calculations which is easy or complex. It can perform more millions instructions per second.

2. Accuracy:

There is no error in calculations from computer. It provides error when a person give the wrong instruction to the computer. It provides 100% accuracy if provide input is right.

3. Diligence:

It can perform any task continuous without tired and provide the accurate result without tired. This type of computer ability in human work there has been a lot of development.

4. Storage Capacity:

It can store a lot of data and information and it has in built memory where it can store lots of data. We can store data in other devices known as secondary devices like floppy, optical disks.

5. Versatility:

Computer is known as versatile device because they perform multiple different tasks at the same time.

6. The ability to take a variety of instructions for execution of tasks.

7. The ability to use simple logical rules to make decisions for their internal control of for the control of some external activity.

8. The ability to communicate with other computer systems.

Anatomy of a computer:

There are 5 major functional units of a digital computer are:

1. Central Processing Unit (CPU)

2. Inputs Units

3. Output Units

4. Storage units

5. Communication interface

CPU is the brain of a computer. The other parts are used to transfer data and to communicate with the CPU. The CPU constitutes the main memory, control unit and arithmetic logic unit.

The five units are explained in below:

Inputting: It refers to the process of entering data into the computer by an input device like keyboard.

Storing: It refers to storage of data and instructions in the computer’s main memory for manipulations.

Processing: It refers to performing operations or manipulation of data entered into the computer so that useful information may be gathered from the entered data.

Output: It refers to the process of showing the information or result to the user either on screen or on paper.

Controlling: It refers to directing all the above processes in coordination. This controlling is done by control unit.

Block Diagram of Computer:

In this figure, the solid lines are used to indicate the flow of instructions and data. The dotted lines represent the control exercised by the control unit. .The figure shows the basic arrangement of the different units of the computer. These five units correspond to the five basic operations known as inputting, storing, processing, outputting and controlling data, carried out by all computer systems.

Generation of Computers:

First Generation Computer

Year: 1944 to 1959

Circuitry: Vacuum Tubes

Devices: Calculators


Developed by: Mauchly and Echert

Second Generation Computer

Year: 1960 to 1964

Circuitry: Transistor

Devices: Mainframes

Processors: System/360, IBM, Bunch

Developed by: John Barden, William Brattain and William Shockley

Third Generation Computer

Year: 1965 to 1975

Circuitry: Integrated Circuits (IC)

Devices: Timesharing, minicomputer

Processors: PDP, System/32, System/36

Developed by: Jack Kilby

Fourth Generation Computer

Year: 1975 to 1990

Circuitry: Very large scale integration (VLSI) and the Microprocessor

Devices: Microcomputer, Embedded computer, personal computer

Processors: VAX, AS/400, Intel Motorola, MOS, Zilog, WDC, Pentium, ARM architecture, MIPS, SPARC

Developed by: Ted Hoff

Fifth Generation Computer

Year: 1990 to till now

Circuitry: Small computer System Interface (SCSI), Video electronic standard Association

Devices: Super Computers, Mainframe Computer, Mini Computer, Personal computer, Mobile Computer, Power PC, PowerMacs, Play Station

Processors: Commodore, UNIX System, Intel Pentium, Pentium MMX, Pentium 2, AMD, Athlon, Pentium 3, Pentium 4.

FAQ for Computer:

Q. What is full form of computer?

Ans. The full form of computer is Commonly Operated Machine Particularly Used in Technical and Educational Research.

Q. Who is father of computers?

Ans. Charles Babbage is known as father of Computer.

Q. How many generation of computer?

Ans. 5

Q. What is full form of CPU?

Ans. The full form of CPU is Central processing unit.

Q. What is the full form of ALU?

Ans. The full form of ALU is Arithmetic logic unit.

Q. What is brain of computer?

Ans. CPU is the brain of computer.

Q. What is the full form of RAM?

Ans. The full form of RAM is Random Access Memory.

Q. What is the full form of ROM?

Ans. The full form of ROM is Read Only Memory.

Q. What is the full form of PROM?

Ans. The full form of PROM is programmable read only memory.

Q. What is the full form of EPROM and EEPROM?

Ans. The full form of EPROM is Erasable programmable read only memory and EEPROM is electrically Erasable programmable read only memory.

Q. What is the full form of CD and DVD?

Ans. The full form of CD is Compact disk and DVD is digital video disk or digital versatile disk.

Q. What is the full form of WORM?

Ans. The full form of WORM is Write Once Read Many.

Q. What is the full form of OMR?

Ans. The full form of OMR is Optical Mark Reader.

Q. What is the full form of MICR?

Ans. The full form of MICR is Magnetic ink character Recognition.

Q. What is the full form of OCR?

Ans. The full form of OCR is Optical Character Reader.

Q. What is the full form of CRT?

Ans. CRT is Cathode Ray Tube.

Q. What is the full form of TFT or LCD?

Ans. TFT is Thin Film Transistor and LCD is Liquid Crystal Display.

Q. What is the full form of ASCII?

Ans. The full form of ASCII is American Standard code for information interchange.

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