Types of Computer

Generally, when we talk about computers, we mean a digital computer but in fact, the computer can be classified into three categories and they are:
(1) Analog Computer   (2) Digital Computer  (3) Hybrid Computer

(1) Analog Computer:  

      Analog computer measures and answers the questions by following the method of “HOW MUCH”. The input data is not a number, digit or character but infact a “PHYSICAL QUANTITY” like mass, acceleration, temperature, speed, pressure etc. and which is always in continuous form.

Applications: These are especially designed for Industrial applications like Petroleum Refineries, Chemical Plants, Electronic Power Plants.

Examples: Analog thermometer, Pressure gauge , speedometer, Electricity meter, Weighing machine, etc.

(2) Digital Computer:

     Digital computer counts and answers the questions by following the method of  “HOW MANY”. The input data is represented by number, characters and digits and which is always in steps. These are also performing the logical and arithmetical operations on the input data.

Applications: These are designed for a various field like: Mathematics, Engineering’s, Statistical, Operations, Researches, Defense, Accounting, etc.

Examples: Unit Record Machine, Electronic Data Processing Machine, etc.

    (i) Special Purpose Computer

          These are specially designed to handle a particular data processing task efficiently. The instructions which are needed to perform that particular task are permanently stored into the memory of the machine.

Applications: These are specially designed for space works like in Air Craft, Satellites, Space Ships, ATM,  etc. as well as for Navigational purpose like in ships, submarines, Built-in GPS of Car, etc.

    (ii) General Purpose Computer

           These are designed to handle variety of tasks and the instructions which are needed to perform any task are not permanently stored into the memory of the machine but they are read from input and kept in memory until the task is completed.

 Applications: These computers are designed for all kind of Official, Commercial, Engineering, and Mathematical works etc.

General-purpose computers can also be divided into four main types:

       (a) Microcomputer
          Microcomputers are also called Personal computers (PC). Microcomputers are single-user computers with their CPU on a single chip called the Micro Processor. These computers have revolutionized the computer industry because of their size and cost. Microcomputers can be used at home, in offices, business places, hotels and laboratories etc. for various purposes.

       (b) Minicomputer
          Minicomputers were introduced in the 1960s. These computers are more powerful than microcomputers and support more than one user at a time. The keyboard and the monitors are remotely kept from the main processor, connected by links in a microcomputer. These multi-user machines have a larger main and secondary memory as they can store large amounts of data for very fast processing.

           These computers are mainly used for data processing, industrial applications, invoicing and stock control of a factory, departmental computers of large organizations, banking and airlines. They offer a limited range of peripherals and software.

       (c) Mainframe computer
            Mainframe computers are the largest computers, available in different models, capacities and prices. The capacities of the early mainframe computers and today's computers are entirely different. Today's mainframe computers are very powerful as compared to the earlier versions.

       (d) Super computer

           Super computers are the most powerful category of computers. These are very expensive and are used for weather forecasting, computer 3D modeling, etc. Super computers are the fastest and most expensive computer systems in the world. They are considered to

be the resources of any nation. Super computers are multi-processor systems that simultaneously process data.
   

           Super computers are manufactured by very few companies in the world like IBM, Cray, Hitachi, Fujitsu, etc.
       

(3) Hybrid Computer: 

They combine the best features of analog and digital and have the speed of both. The computers which have qualities of both digital and analog computers are called hybrid computers. Hybrid computers have the speed of analog and the accuracy of digital computers. They are used for special problems in which the input data, a form of measurement is converted into digital and processed by computer.

The main examples are Central National Defence and Passenger Flight Radar Systems which are Hybrid Computer. They are also used to control robots on the production line in CAM (Computer Assisted Manufacturing).