IGCSE THEORY

Hardware

The physical components of the system. For example a phone.


Software


Set of commands that are processed for an output. For example utility software which is used to change the system (control panel or system preferences). Application software such as Word Processing and Call of Duty. The operating system is also software, it is used so everything such as the printer and word can function and work together.


Components


Input devices: CPU (central processing unit), ROM (read only memory) is non volatile and is permanent, RAM (random access memory) holds what you are currently doing such as playing a game, it's continously changing and is volatile. RAM and ROM are primary memory, secondary storage is the hard drive.


Output devices: Printers such as laser.


Interface


GUI's (graphical user interface)  are WIMP's (windows, icons, menu's, pointers) and Command line interface.

Types of Computers

• The big computer is called a mainframe used for bulk processing.
• Palmtop otherwise known as a netbook is a small laptop.
• Normal computer is  personal computer (PC)- desktop computer
• Personal digital assistant (PDA). An iPhone without the phone.NOT a phone.

Mainframe example: