DEFINITION OF COMPUTER
A computer is an electronic machine, basically works on IPO cycle. IPO cycle means Input, Processing and Output cycle. First it takes input or instruction by users then process it and finally gives the output. It can calculate numbers, arrange, store and find information or can regulate other machines etc.
FEATURES OF COMPUTER
- Speed : It has very high speed than a human being
- Accuracy :It works with 100% accuracy in no time.
- Diligence : It can perform repetitive task without getting tired.
- Versatility : It can perform more than one function at a time.
- Memory : It has storing capability, which stores our day to day work and we can find out easily whenever required and edit them.
According to its features, sizes and functions, a computer is of many kinds.
Types of a computer
We can categorize a computer on the basis of
1. Data Type
2. Purposes and
3. Its functionality
1. According to data type there are three types of computers.
i. Digital computer
ii. Analog Computer and
iii. Hybrid computer
i. Digital Computer : It works on binary number system (ex. '0' and '1'). Many complicated tasks are performed using these binary number system. It processes the data represented in discrete (data with proper space between them). The hierarchical three processes of digital computer are
1. Input 2. Process and 3. Output
It is more accurate than an analog computer. The first digital computer was made in 1945, the name is ENIAC.
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| ENIAC IN 1945 |
ii. Analog Computer : It operates on changeable physical quantities like mechanical, electrical etc.
It works on continuous value instead of discrete. These continuous values make an analog signal. It has limited capacity to accept and compute the problems. It is less accurate than a digital computer. Example is Oscilloscope used by engineer to make measurement.
iii. Hybrid Computer : Hybrid Computer provides functions and features of both analog and digital computers. The main aim to produce a combine or hybrid computer is to incorporate the most beneficial aspects of both the computer analog and digital.
It is more versatile, gives more accurate, detailed and practical results. Processing speed is also high in compare with their predecessors.
The limitations are : The cost is higher than both the analog and the digital computers. It requires expensive circuit, cable, networks etc.
2. According to purposes there are main four types of computers. These are
i. Microcomputer
ii. Minicomputer
iii. Mainframe and
iv. Supercomputers
i. Microcomputer
These are commonly known as PC (Personal Computer). Such computers are useful for single user and occupies less space but can perform all the basic functions. It has basic input/output devices and a CPU cabinet in desktop computer. All the circuitry mounted on the single PCB. Examples are Smart Phone, Palmtop, Tablet, Laptop, Desktop Computers etc.
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| Smartphone |
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| Palmtop |
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| Laptop |
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| Tablet |
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| Desktop |
ii. Minicomputer
Minicomputers are more powerful and expensive than microcomputers but less powerful and cheaper than mainframe and supercomputers. These are useful for more than one users. Such computers are used in business transactions, database management in large organisations, file handling, scientific and engineering researches etc. These are emerged as more powerful. Generally we see these kinds of computers on the billing counters of malls, large storage etc.
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| Minicomputers |
iii. Mainframe Computers :
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| Mainframe Computer |
iv. Supercomputer :
