Most all volatile memory is dynamic RAM because it uses only one transistor and one storage capacitor for each bit. It is denser and much less costly than "static RAM," its faster counterpart.

In contrast, the main memory in a computer is typically dynamic RAM (DRAM). Static RAM chips have access times in the 10 to 30-nanosecond range, while dynamic RAM is usually above 50 ns.

SRAM memory modules use static random access memory (SRAM), a type of memory that is faster, more reliable, and more expensive than dynamic random access memory ... Asynchronous static RAM- ...