Hardware components of the PC
Main Memory
RAM (Random Access Memory)

RAM gets its name from the fact that any location of main memory can be randomly selected to store or retrieve data and then directly accessed by the CPU. Dynamic RAM (DRAM) is the most common type of RAM memory, and it is dynamic because it requires its storage cells to be electrically recharged or refreshed every few milliseconds or data will be lost. Static RAM (SRAM) is RAM that does not need refreshing, because it operates on moving current that is switched in either of two directions rather than a DRAM cell holding a charge. When the main power to the computer is off, any information stored in RAM is lost.