Types of Memory

Random Access Memory

Random Access Memory (RAM) is one of the two types of main memory found in computers. General purpose computers usually contain a large amount of RAM. The features of RAM are:

• Volatile - RAM is volatile. This means that it will lose its contents when power is lost (i.e. if the computer is switched off).
• Fast - RAM is much faster to access than secondary storage such as Hard Disk Drives (HDDs).
• Expensive - RAM is much more expensive per unit capacity than secondary storage media.
• Random access - Random Access means that any part of the memory can be accessed as quickly as any other part of the memory.

Read Only Memory

Read Only Memory (ROM) is another type of main memory found in computers. It comes on a small, factory made chip in the motherboard. Features of ROM include:

• Non-volatile - ROM is non-volatile. This means that ROM keeps its contents when power is lost.
• Read only

ROM is often made from flash memory. This means that it's contents cannot be changed easily.

This means that the ROM only stores small programs that boots or starts up the computer.

These programs are called the Basic Input Output System (BIOS).

They usually:

• Load an operating system.
• Check the system for errors.