Computers - EdexcelThe role of main memory

Memory is the component of the computer that holds data and programs.

Memory is internal to the computer. As a result, data can be read from and written to main memory extremely quickly. This gives the central processing unit (CPU) fast access to the data and instructions that the memory holds.

There are three types of main memory:

• read only memory (ROM)
• random access memory (RAM)
• cache memory

ROM is non-volatile, whereas RAM and cache memory are volatile. Non-volatile memory keeps its contents even when the computer is switched off. However, volatile memory loses its contents when the computer has no power.

Main memory is limited in size, especially when compared with secondary storage.