ReRAM (RRAM) is non-volatile memory, meaning that it retains data even when power is turned off. SRAM is volatile, meaning that it loses data when the power is off.
SRAM is faster than DRAM and NVMs and has low latency, so it is often used in real-time applications as level-1 (L1) tightly coupled cache memory. However, SRAM is expensive, low-density, and power-hungry. A typical SRAM cell requires six transistors, while a ReRAM cell requires only a single transistor. For that reason, the overall memory density of ReRAM is typically 3-4 times higher than that of SRAM.
While ReRAM is slightly slower, its lower cost, higher density, ability to retain data when powered down and its lower standby energy consumption make ReRAM more suitable for embedded, edge, and low-power use cases.