SRAM – Static Random Access Memory as compared to DRAM (Dynamic Random Access Memory). SRAM, once loaded with data bits retains their values as long as power is being supplied without being actively refreshed as is the case with DRAM. That enables SRAM to have better performance than DRAM but also makes it more expensive. SRAM has a larger size than equivalent capacity DRAM. It is often used for level 1 and level 2 CPU caches because of its speed.
SRAM uses a flip-flop circuit with two stable states to store a binary bit value. The circuit needs four transistors to store a bit and two to control access to the cell. In contrast DRAM needs one transistor and one capacitor to store a bit, making its cells smaller than SRAM cells.