Dynamic RAM is typically the RAM used as the main memory in a computer system. DRAM requires fewer transistors per bit than SRAM, but each bit needs to be refreshed regularly or it will lose information. DRAM is typically slower but much less expensive than SRAM
Static RAM is used for the cache memory and registers in computer systems. SRAM typically requires four or six transistors per bit, making it substantially more expensive than DRAM, which usually requires one transistor per bit. SRAM is able to operate at higher speeds than DRAM, and does not require refreshing
the most common computer memory which can be used by programs to perform necessary tasks while the computer is on; an integrated circuit memory chip allows information to be stored or accessed in any order and all storage locations are equally accessible