About Computer

Computer

The word “computer “came from the word compute which means to “calculate”
Thus the term computer is used for any calculating device however in every day life this term is used for an electronic computer.

Definition:

Computer is define an electronic machine which is used to store, retrieve, and process data according to a set of instruction given to it.

Types of Computer
Computers can be divided into following types on the basis of there working

There are three types of computer
Analog Computer
Digital Computer
Hybrid Computer

Analog Computer:
An Analog Computer does not operate with digital signals. It recognizes data as continues measurement of physical property. It has no state. Analog computer is difficult to operate and use. Its output is usually displayed on meter or graphs. Voltage, pressure, speed and temperature are some physical properties that can be measure in this way. Analog computer has low memory and fewer functions. It is usually built special purposes. Analog computer is mainly use in the field of engineering and medicine. Examples:
Analog clock measure time by the distance of the hands of a clock around a dial
The speed of the car is measured by the Speedo meter
Analog processor is used as petrol stations to indicate quantity of petrol delivered

Digital Computer:

A digital computer works with digits. Everything is described in two states i.e. either on or off. The number 1 represents on or 0 represents the off states. It operates by counting numbers or digits and gives output in digital form. The digital computers are very fast. They can be programmed to perform mathematical calculations, compare values etc.
These computers store results in digitals format. Digital computers are manufactured in a wide variety of sizes speeds and capacities. They have big memory. Digital computers are commonly used in office an educational institutions. Apple Macintosh and IBM Pc is two important digital computer

Examples:
Digital watch is good example of digital computers. It displays the time that does not vary continually but changes from one describe values to others.
Score board that directly count discrete values such as time left to play and the score of each team.

Hybrid Computers:

A hybrid computer is a combination of both Analog and digital computer.
A hybrid computer combines the best characteristics of both the Analog and digital computers.
It can accept data in Analog and digital and digital form
Example:
Hybrid computer device may calculate patients heart functions, temperature, blood pressure etc. this measurement can be converted and displayed in digital form.


Difference between Analog and Digital Computers:

The Difference between Analog and Digital Computers is as follows:


Analog Computers Digital Computers
1. It provides us continues value
2. It represents physical quantities in the form of waves or in continuous form
3. It has no state
4. It is difficult to use
5. It has low memory
6. It has slow speed
7. It is used in engineering and science
8. It is used to calculate analog quantities like speed, weight, height
9. It is less reliable
10. Examples are Thermometer, analog clock  etc. 1. It provides us discrete value
2. It represent physical quantities with the help of symbols or number
3. It has two states on [1] and off [0]
4. These computers are easy to use
5. These computer have big memory
6. These computer have fast speed
7. It is used in all fields of life
8. It is used to calculate mathematical and logical operation like addition, multiplication etc.
9. It is more reliable
10. Examples are digital clocks, and laptop computer and micro computers


Reference: This Data collected from URL: http://amazingpctricks.blogspot.com
Ali Faizan Hameed
Muhammad Numan