Memory

Memory is how machines store data. There is volatile memory which is lost when power is cut, and there is non-volatile memory which persists even after shutdown.

RAM

Why is it called Random-Access

• Because like an array, memory can be randomly accessed from any address at any time.
• It would be more appropriate to call it read-write memory as opposed to ROM (read-only memory).

SRAM

Used for caches

• static memory that doesn't discharge voltage over time.
• much more expensive
• uses more power
• takes up more space

DRAM

Used for main memory

• needs periodic recharges to continue to store data
• much less expensive
• uses less power
• takes up less space (more dense)