history of the internet

 BRIEF HISTORY OF THE INTERNET

During the 1960s ,The US defense department made an experiment that led them to the development of connected computer networks that should work as a coordinate whole.

Their purpose was to help their scientist and researchs from widely dispersed areas work as if they were in one place by sharing their files and resources.

A " cold war" existed at that time, and networks were not secured from enemy attack. Their solution was to build a  "bombproof" network, one that would be operational even when other parts of the networks were shut down. 

From this requirement , the defense department created the ARPANET(Advanced Research Projects Agency Network) in 1969 it was an experimental network based on packet switching techniquies..

computer parts and their uses

Computer parts and their uses

You can go to: 

https://m.youtube.com/watch?v=yYA5DP_zPu0

For more info.

computer system

COMPUTER SYSTEM

Computer system unit is the enclosure that contains the main components of a computer. It is also referred to as computer case or tower. Read on to learn about the functions and components that go into a computer system unit.

Definition

A typical desktop computer consists of a computer system unit, a keyboard, a mouse, and a monitor. The computer system unit is the enclosure for all the other main interior components of a computer. It is also called the computer case, computer chassis, or computer tower. Cases are typically made of steel or aluminum, but plastic can also be used. While most computer cases are rather dull, black, metal boxes, some manufacturers try to give the unit some flair with color and special design eleme

Functions

The primary function of the computer system unit is to hold all the other components together and protect the sensitive electronic parts from the outside elements. A typical computer case is also large enough to allow for upgrades, such as adding a second hard drive or a higher-quality video card. It is relatively easy to open up a computer system unit to replace parts and install upgrades. In contrast, it is quite difficult to open up a laptop computer, which is not designed with replacements and upgrades in mind.