1 of 34

Classification of Computer

Computers are classified based on the size, type and capacity of their work, which is called classification of computers.

Another name of the classification of computers is known as classes of computers. There are many types of computers available nowadays.

Computers are also available in a different size, different capacity and different type.

Classification of computers is particularized in three main categories.

Classification of Computers On the Basis of Size and Capacity.

Classification of Computer On the Basis of Type.

Classification of Computer According to Purpose.

2 of 34

Computer Memories

Store data and instruction. Memory system can be divided into 4 categories:
CPU register
Cache memory
Primary / Main memory
Secondary Memory / Mass Storage
They can be represented in an hierarchical form as:

4 of 34

Primary / Main memory & Secondary Memory / Mass Storage

Primary / Main memory: Primary memory is the computer memory that is directly accessible by CPU. It is comprised of DRAM and provides the actual working space to the processor. It holds the data and instructions that the processor is currently working on.

Secondary Memory / Mass Storage: The contents of the secondary memory first get transferred to the primary memory and then are accessed by the processor, this is because the processor does not directly interact with the secondary memory.

5 of 34

Now, Let’s see the difference between Primary memory and Secondary memory:

Primary memory	Secondary memory
Primary memory is temporary.	Secondary memory is permanent.
Primary memory is directly accessible by Processor/CPU.	Secondary memory is not directly accessible by the CPU.
Nature of Parts of Primary memory varies, RAM- volatile in nature. ROM- Non-volatile.	It’s always Non-volatile in nature.
Primary memory devices are more expensive than secondary storage devices.	Secondary memory devices are less expensive when compared to primary memory devices.
The memory devices used for primary memory are semiconductor memories.	The secondary memory devices are magnetic and optical memories.
Primary memory is also known as Main memory or Internal memory.	Secondary memory is also known as External memory or Auxiliary memory.
Examples: RAM, ROM, Cache memory, PROM, EPROM, Registers, etc.	Examples: Hard Disk, Floppy Disk, Magnetic Tapes, etc.

6 of 34

The following table differentiates ROM and RAM:

Difference	RAM	ROM
Data retention	RAM is a volatile memory which could store the data as long as the power is supplied.	ROM is a non-volatile memory which could retain the data even when power is turned off.
Working type	Data stored in RAM can be retrieved and altered.	Data stored in ROM can only be read.
Use	Used to store the data that has to be currently processed by CPU temporarily.	It stores the instructions required during bootstrap of the computer.
Speed	It is a high-speed memory.	It is much slower than the RAM.
CPU Interaction	The CPU can access the data stored on it.	The CPU can not access the data stored on it unless the data is stored in RAM.
Size and Capacity	Small size with less capacity.	Large size with higher capacity.
Used as/in	CPU Cache, Primary memory.	Firmware, Micro-controllers
Accessibility	The data stored is easily accessible	The data stored is not as easily accessible as in RAM
Cost	Costlier	cheaper than RAM.
Storage	A RAM chip can store only a few megabytes of data.	A ROM chip can store multiple gigabytes (GB) of data.

8 of 34

Classification of Computer by Type�

The computer is classified into three parts based on Type and the basis of Hardware Design and Data Handling.�You can also call it the classification of computers by functionality.�These computer different roles in different fields.�Classification of computer according to type is given below.�Analog Computer�Digital Computer�Hybrid Computer�

Analog Computer

Analog computer is used to measure the physical quantities, temperature, pressure weight and height and gives the result in the form of digits is called analog computer.

Analog computers are used by civil engineers, mechanical engineers and electrical engineers. Needle clock is an example of analog computer.

9 of 34

Analog Computer

10 of 34

There are different types of Analog Computer is given below.

Castle Clock - A clock that tells time with a needle is called a castle clock. This clock is originally from the top of a palace. This watch was invented by Al-Jazari.

Slide Rules - A slide rule is a type of mechanical analog computer. Slide rules are mainly used to perform operations such as multiplication and division, exponentiation, roots, logarithms, and trigonometry.

Differential Analyzers - A differential Analyzer is also a mechanical analog computer, used in the early and mid-20th century. Differential analyzer Analog computers were designed to solve differential equations.

Electronic Analog Computers - It is also a type of analog computer itself, electronic analog computers use the continuously varying aspect of physical phenomena such as electrical, mechanical, or hydraulic quantities to solve a problem.

Hydraulic Analog Computer - It is also a type of analog computer, in that computers model data by using the flow of liquid rather than the motion of mechanical parts.

Pneumatic Analog Computer - It is also a type of analog computer and these analog computers use compressed air as the power source, which is very simple and inherently analog, and such computers are mostly used in non-residential building areas.

Mechanical Analog Computers - It is also a type of analog computer, mechanical analog computer consists of various components. Such as gears and levers, electronic parts are not used in this computer.

11 of 34

Digital Computer�

Digital computers are used to calculate digits. Today digital computers are being used in everywhere.

The device in which you are reading this post is also a form of a digital computer.

Such computer devices that work on numbers 0 and 1, those computers are called digital computers.��In digital computers, information is represented in bits. At present, the whole world is using digital computers tightly to do any work.��Digital computers are very powerful devices and are also the most used electronic devices. A digital computer is a device that processes any kind of data by converting it into machine language ( 0 and 1 ).��The present-day digital computers are multitasking i.e. on these digital computers you can do many things simultaneously at the same time.

Smart Phone and Laptop are example of digital computer.

12 of 34

Digital Computer

13 of 34

There are different types of Digital computer is given below.�

Personal Desktop Computers - Those who use the computer for personal use are called personal computers. Desktop computers, laptop computers, and notebooks are all forms of personal computers.

Calculators - A calculator is an electronic device. You can do many types of math's calculations using a calculator. For example - addition, multiplication, subtraction, or division can be done.

Laptops - A laptop is a portable computer. We have told in detail about the laptop in this post.

Digital watch - A digital watch is also a form of the digital computer, because the digital watch does not tell time through a needle, but the digital watch tells time through numbers on a screen. A digital watch is also known as a smart watch.

Smartphones and Tablets - Smartphones and tablet computers are both forms of digital computers. Smartphones and tablets are both very powerful and they have many great features. Smartphones are smaller in size than tablet PCs.

Workstations - Workstations computer is also a form of digital computer. Workstations computers are much more powerful than any other general computer. How professional people use these computers.

Digital clock - The digital clock is also a type of computer, which is used to see the time. You must have often seen your digital clock hanging on the wall. A digital clock is always hanging on the wall itself.

14 of 34

Hybrid Computer�

Hybrid computer combine the both analog or digital computer which includes both Analog and Digital properties. Hybrid computer is used in medical field.
There were some problems that both analog and digital computers were not able to solve, due to which hybrid computers were created. Because of the work that analog and digital computers cannot do today, hybrid computers can do.��Hybrid computers are more powerful than analog and digital computers.
Smart watch is an example of Hybrid Computer.

15 of 34

Hybrid Computer

There are three types of Hybrid computer is given below.

Large Electronic Hybrid Computer

General-Purpose Hybrid Computers

Special-Purpose Hybrid Computers

�

16 of 34

Classification of Computer According to Purpose�

The computer is classified into two parts According to Purpose. Every computer is designed with different design and different purpose.��Every computer is designed for a particular place and for some specific purpose.

Classification of computers by purpose is given below.

Special Purpose computer
General Purpose computer

17 of 34

Special Purpose computer�

They Are Made To Successfully Meet The Requirement Of Particular Task Or Application, It Incorporates The Instruction Needed Into The Design Of Internal Storage.��So That It Can Perform The Given Task On A Simple Commands.��Automatic Teller Machine (ATM) is an example of Special Purpose computer.

18 of 34

There are many different types of Special Purpose computer is given below.�

Washing machines
Surveillance equipment
Traffic-control computers
Oil-exploration systems
Weather-forecasting simulators
Military planes controlling computers

19 of 34

General Purpose computer�

This Instruction Needed To Perform A Particular Task Is Not Storage Permanent.
When One Job Is Completed Instruction For Another Job Can Be Loaded Into The Internal Memory For Processing.
Thus A General Purpose Machine Can Be Used To Prepare Pay Bill, Inventory Counters, and Print Report etc.
All microcomputers are examples of general purpose computer system.

20 of 34

Classification of Computers On Basis of Size and Capacity�

The computer is classify into four parts based on size and capability.
The classification of computer according to size and capability of computer is given below.
Micro Computer
Mini Computer
Main frame computer
Super Computer

21 of 34

What is Super Computer�

The super computers are the most high performing system. A supercomputer is a computer with a high level of performance compared to a general-purpose computer.
The actual Performance of a supercomputer is measured in FLOPS(Floating-point operations per second) instead of MIPS(Million instruction per second).
All of the world’s fastest 500 supercomputers run Linux-based operating systems.
Supercomputers actually play an important role in the field of computation, and are used for intensive computation tasks in various fields, including quantum mechanics, weather forecasting, climate research, oil and gas exploration, molecular modeling, and physical simulations. and also Throughout the history, supercomputers have been essential in the field of the cryptanalysis.
E.g.: PARAM, jaguar, roadrunner.

22 of 34

Super Computer

These all examples of Famous Super Computers are:-

CRAYX-MP, CRAY-2, CRAY-3, ETA-10,Jaguar, Titan, Nebulae, IBM Roadrunner, K Computer, Tianhe-I, Jugene, Kraken, PleIades, IBM Sequoia.

23 of 34

Mainframe computers

These are commonly called as big iron, they are usually used by big organizations for bulk data processing such as statics, census data processing, transaction processing and are widely used as the servers as these systems has a higher processing capability as compared to the other classes of computers.
Most of these mainframe architectures were established in 1960s, the research and development worked continuously over the years and the mainframes of today are far more better than the earlier ones, in size, capacity and efficiency.
Eg: IBM z Series, System z9 and System z10 servers.

24 of 34

Mainframe computers

25 of 34

Mini computers

These computers came into the market in mid 1960s and were sold at a much cheaper price than the main frames.
They were actually designed for control, instrumentation, human interaction, and communication switching as distinct from calculation and record keeping, later they became very popular for personal uses with evolution. �In the 60s to describe the smaller computers that became possible with the use of transistors and core memory technologies, minimal instructions sets and less expensive peripherals such as the ubiquitous Teletype Model 33 ASR.
They usually took up one or a few inch rack cabinets, compared with the large mainframes that could fill a room, there was a new term “MINICOMPUTERS” coined.
Eg: Personal Laptop, PC etc.

26 of 34

Mini computers

27 of 34

Micro computers

A microcomputer is a small, relatively inexpensive computer with a microprocessor as its CPU.
It includes a microprocessor, memory, and minimal I/O circuitry mounted on a single printed circuit board.
The previous to these computers, mainframes and minicomputers, were comparatively much larger, hard to maintain and more expensive.
They actually formed the foundation for present day microcomputers and smart gadgets that we use in day to day life.
Eg: Tablets, Smartwatches.

28 of 34

Micro computers

29 of 34

Personal Computers�

Personal Computers refers to any computer that is meant to be used by a single person only.
Personal Computers are also called Microcomputers as they are the smallest computers for personal use.
The term PC is most commonly used to refer to a Desktop Computer.

Types of Personal Computers

The seven main types of Personal Computers are:

Desktop Computers
Workstations
Laptop Computers
Notebook Computers
Tablet Computers
Handheld Computers
Smartphone Computers

30 of 34

Desktop Computers�

The most common type of Personal Computer
Commonly used in workplaces, schools and homes.
Owing to their large size they are difficult to carry around.
Is designed to make it sit on a table or desk that’s why it’s called a Desktop Computer
Desktop Computer performs a multitude of tasks ranging from communication, photo editing, playing games, watching videos and much more.
The main component of a Desktop Computer is the System Unit.
System Unit is the case that houses critical parts of desktop PC such as processing and storage devices.
System Units generally available in two models

Originally Oriented System Unit
Vertically oriented system Unit also called as tower model.

31 of 34

Workstations�

A desktop computer but with more powerful processing additional memory and graphics handling capabilities than a standard desktop PC and thus more speedy.
Optimized for scientists, engineers, animators, who need a system with greater average speed and power to perform sophisticated tasks such as 3D graphics and game development.

32 of 34

Laptop Computers & Notebook Computers��

People normally place these devices on their laps, hence the name laptop computer.
Those who require the power of full-size desktop computers can avail themselves of laptop computers because they are microcomputers in the true sense.
Owing to their small size and portability, laptops belong to the category of mobile computers.
Mobile computers are easy to carry around because of their small size.
Some laptop systems are designed to be plugged into a docking station, including a full-size keyboard and mouse or other devices.
Docking stations also provide additional ports that enable the laptop to be connected to different devices or a network in the same manner as a desktop computer.

Notebook Computers

Notebook computers are the same as laptop computers exact for they are smaller and lighter than laptops.

33 of 34

Handheld Computers- Palmtops�

Computers are small enough to fit in your hand or placed in your pocket.
Most common example is the personal Digital Assistant (PDA) which is nothing more in size than a small appointment book.
PDAs are used for notes taking maintaining a list of telephone numbers and addresses and keeping oneself informed of important dates and agenda items.
May be synchronized with a Desktop Computer to Exchange Data.
Some PDAs allow users to write on the screen using a pen.
Provide features such as access to the internet using a wireless connection, global positioning systems, music players and digital cameras and can include a cell phone.
Some PDAs allow voice input.