1. TYPES AND COMPONENTS OF COMPUTER SYSTEM

2. Hardware
Hardware is a general term of the physical components that make up a computer system like keyboard, mouse, monitor, processor, circuit board,etc

3. Software
Software is a general term for the programs that control the computer system. There are two types: systems and application.

4. Main components of computer system
A typical computer system is made up of hardware and software.
Example:
-Input devices: keyboard, mouse.
-Output devices: monitor, printer.
-Secondary storage devices: DVD R/W drive, removable hard drive.

5. Processor and internal memory devices
CPU: the main part of the computer where most calculations take place. Internal hard drive: the computer’s main memory; typically contains the operating system, software applications, and other files. Random access memory(RAM): where data is temporarily stored when running applications. Read only memory(ROM):memory used to store information that needs to be permanent.

6. Operating system
It’s most important program that supports a computer's basic functions aka the brains.
General tasks:
-Controlling the operation of the input, output and backing storage devices.
-Supervising the loading, running and storage of application programs.
-Dealing with errors in applications programs.
-Maintaining security.
-Maintaining a computer log.
-Allowing communication between user and the computer system.

7. Types of user interface
Command line interfaces
Graphical user interfaces

8. Command line interfaces
Allow users to type in instructions in order to choose options from menus, open software, etc
Disadvantages:
- Users have to learn a number of commands before they can carry out basic operations.
- It is slow having to key in these commands every time an operation has to be carried out.
Advantage:
-The user is in direct communication with the computer and is not restricted to a number of pre-determined options.

9. Graphical user interfaces
Allow users to interact with a computer(or MP3 player, gaming devices, mobile phone, etc) using pictures or symbols rather than having to type in a number of commands.
Uses various technologies and devices to provide the user interface. One of the most common is window icons menu and pointing device. This uses a mouse to control a cursor, which then selects icons to open up windows.

10. Types of computers
Laptop: a type of computer where the monitor, keyboard, pointing device and processor are all together in one single unit. Ad: portable, full advantage of wifi. Dis: easy to steal, limited battery life. Netbook: a computer that can almost fit onto a hand. Ad: same features as laptop Dis: don’t have optical drives, keyboards are small.

11. PC/Desktop: a general purpose computer which is made up of separate monitor, keyboard, mouse, and processor unit. Ad: the large casing allows good dissipation of any heat build-up. Dis: Aren’t portable, need to be hooked up by wiring. Personal digital assistants: small handheld computers that usually come with a touch screen that is activated using a stylus. Ad: can be used anywhere, lightweight Dis: difficult to enter text quickly, limited capabilities.

12. Mainframe computers A large, powerful computer system. Uses:
-can have several CPU
-very fast processor speeds.
-can support multiple operating systems.
-have huge amounts of storage capacity.
-huge internal memories.
-often operating using time sharing or patch processing.
Ads:
-can be used to do a large job.
-capable of very large number, crunching
Dis:
-very expensive to to operate and maintain.
-not portable

13. T H A N K Y O U !