CertiGuide to A+ (Core Hardware)  9  Chapter 0011:  System Memory       9  II  Memory Types

Electronically Erasable Programmable Read Only Memory (EEPROM) 1 Static RAM (SRAM)

The next type of system memory that you will find in every PC is Random Access Memory, or RAM. RAM is much faster than ROM however. A typical performance enhancement to any PC is to have the contents of the ROM BIOS copied into RAM. This is known as shadowing the BIOS. By having the BIOS program in RAM, it is available more quickly for the operating system to utilize.

Unlike ROM, RAM can be read from and written to by the processor at any time. However, RAM requires power from the system in order to keep the instructions and data that it contains. If the power to the system is removed, the contents of the RAM are lost. Therefore, RAM is often referred to as volatile memory.

Much like ROM, RAM comes in many different types, sizes, and speeds. The most basic delineation between types of RAM is Static RAM (SRAM), versus Dynamic RAM (DRAM).

Electronically Erasable Programmable Read Only Memory (EEPROM) 1 Static RAM (SRAM)