classifications of computers

4 classification of computers

Computers are designed for different purposes and to function in a certain way. This gives the bases of how computers can be grouped together using different factors to classify them. The classification overlaps each other such that a computer can be in more than one category.

There are four main classifications of computers where each computer can be categorized. Classifications are processing speed and physical size, purpose, functionality, and computer generation.

Summary list of classification of computers

Way of computer classificationTypes of computersExamples of computers
By size and processing powerSupercomputerFrontier, Fugaku, Summit, Sierra, LUMI, etc.
MainframeUNIVAC, IBM zSeries, System z9, and System z10 servers
MinicomputerPDP-8 and IBM-system-38, IBM’s AS/400e, Honeywell200, TI-990
MicrocomputerDesktop, laptops, palmtops, smartphones, etc.
Classification by purposeGeneral purposeDesktop, laptops, palmtops, workstations, smartphones, etc
Special purposeScientific calculators, mobile phones, digital petrol pumps, some Supercomputers, digital watches, video game consoles, Robots, etc.
Functionality, how they process dataDigital computersDesktop, laptops, palmtops, workstations, smartphones, etc
AnalogVehicle speedometer, Blood Pressure machine, thermometer
HybridUltrasound, monitoring systems, intensive Unit Care system(ICU)
Classification according to historyFirst generationUNIVAC, IBM-701, IBM-650, ENIAC, EDVAC
Second generationIBM 1620, CDC 3600, IBM 7094, CDC 1604
Third generationHoneywell-6000 series, PDP (Personal Data Processor),  UNIVAC 1108, TDC-316, and IBM-370/168
Fourth generationMicral, IBM 5100, STAR 1000, CRAY-1, Altair 8800
Fifth generationDesktop, laptops, palmtops, workstations, smartphones, etc

Computer classification according to physical size and processing speed

This category classified computers in terms of physical size, storage capacity, and processing speed.


They are the biggest computer today in the world. Supercomputers process data at a very high speed in billion of processes per second. They also have large memory and storage capacity to store data that they will be processing.

Because of the high processing speed, they have a special cooling system to reduce overheating. This entire system requires a big space hence making them the biggest in the world in terms of all necessary computer components.

They are mostly used for research and in the military for testing weapons. Read more on how they operate.

Mainframe computers

It is the second category and it has a high processing speed but is not as fast as supercomputers. All its components are small than supercomputers but bigger than minicomputers. Mostly they are used as servers by big multinational companies to store data and process.

They allow multiple users to access them at a time. Due to this, they should be able to handle the request that is made by the user without delay to improve business operations.

Mini computers

It is a smaller version of Mainframe and they are used by small and medium companies as servers. The size is smaller than the mainframe but bigger than microcomputers. They support fewer users at a time and processing speeds are all lower than the mainframe. 


It is the smallest computer and they are portable. This type of computer uses a microchip which holds a microprocessor. They include desktop computers, laptops, palmtops etc. They have a microchip as a processor.

Today computers are even becoming smaller. We have smartphones, smartwatches and other devices that are smaller than personal computers.  

Classification according to how computers process data (functionality)

The category uses how devices process data and the types of data they process.

Digital computers

These computers allow digital input of data or convert it to digital before they can process it. If you type a character it is converted to binary (stream of 1`s and 0`s) which it can be able to interpret and then process. Digital computers deal with discrete values which means they don`t recognize the in-between, it is either 0 or 1 ON or OFF. Most of the common computers today are digital.

Analogue computers

The analogue computers deal with continuous values. They are used to measure physical phenomena such as pressure, temperature, speed, voltage etc. When measuring for example voltage we can expect to measure 1.57V depending on the accuracy of your instrument. 

The computer that can be used to allow this kind of input they are called the analogue computer. Examples include a Petrol pump measuring volume and a speedometer for speed among others.

Hybrid computers

These computers combine analogue and digital characteristics. They can be able to input both the discrete and continuous data and it is processed without any itch. For example, it can be able to record the weather phenomenon of a given location (analogue) and use the statistic recorded sometime earlier (digital) to give a conclusion. 

Mostly they can be found in hospitals where they are used to measure patients’ vitals and the data is processed on a digital computer.

Classification of computers according to purpose 

They are categorized in terms of the work they were manufactured to perform. Computers can either be for general use or specific purpose.

Special purpose computers

These are computers that are manufactured to perform a specific task only. Robots used in vehicle assembly lines are special computers. They can only perform that task, if given another task they cannot perform, they are customized for that specific one. Examples include Robots, digital watches, calculators, Petrol pumps, etc.

General purpose

They can perform a range of functions. These computers were designed to perform more than one function. General Computers can be used to control other machines but if also given the task of performing complex calculations they can as well do them. Most personal computers are general computers. They can be used for a range of activities such as calculations, playing computer games, data analysis, watching movies, etc.

Dedicated computers.

Sometimes computers can also the dedication to a specific task. This should not be confused with special-purpose computers. These are general-purpose computers that are dedicated to performing a specific task in a given time. A general computer can be dedicated as a computer game, supermarket cashier desktop, etc.

 Computer classification according to generations

Computer generation shows the evolution of computers from mechanical machines to small digital computers that we have on the market. It gives the history of computers. There are 5 main computer generations so far.

The first generation

These were the earliest computers that were developed after the Second World War around 1946. The device used vacuum tube gadgets to process data. They required a lot of them and hence they were very big in size when you compared with today`s version of the computer.

First generations used to overheat and frequently broke down hence not reliable. They operated very simple calculations because they had so many limitations. A good example of first generation computer is ENIAC (Electronic Numerical Integrator And Calculator).

The second generation

After the world war started the cold war where every country wanted to know what their enemies were up to. This led to the further development of computers to make the processing of information collected from other counties processed fast enough to allow action to be taken. The result is more advanced computing devices.

Second-generation computers were developed around 1958. They used transistors now instead of vacuum tubes. Transistors were small in size and also they processed data faster. These make the computer reduce in size, process faster than in generation one, and became more reliable.

Third-generation computers

As time progressed the computer evolved to more powerful and third-generation computers come around 1965. They combined many transistors into a silicon chip to create even more compact processing components (Integrated Circuit). This reduced the size, increased data processing, and memory and they were more reliable.

The third generation used magnetic disks for the storage of data.

The fourth-generation computers

This generation of computers began around the 1980s. They combine very many transistors into one silicon chip (Very Large Scale Integrated Circuits). The computer was now small to the point of being portable like laptops; they had high processing speed, large memory, and high storage capacity.

Fifth generation

Most current computers in the market are in this generation. They are more advanced with the latest technologies such as Artificial Intelligence, and parallel processing among others. The computers are very fast, small in size, and can store data even in a smaller space.

They use and will use superconductors technology which allows the transmission of data with as minimum resistance as possible. This will mean more powerful devices. Nanotechnology and quantum computing will also be applied to devices to make computers even small but more powerful than what we have today.

The main properties of the computer that are changing as generation progress include the following: 

  • Processing speed which increases;
  • Physical size reduce
  • Main memory capacity increase
  • Processing speed increase
  • Processor technology changes from Vacuum tubes to integrated circuits in a chip
  • Cost of production reduce
  • Secondary storage capacity increases.

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