What is an essential characteristic of static RAM?

Static RAM (SRAM) is characterized by its ability to retain data as long as power is supplied, without the need for periodic refreshing. This is because SRAM uses bistable latching circuitry (flip-flops) to store each bit of data, allowing it to maintain the state of the bits indefinitely while powered. This inherent stability is one of the key advantages of SRAM over dynamic RAM (DRAM), which does require refreshing to maintain the stored data due to its reliance on capacitors that can lose charge over time.

SRAM's design allows for faster access times compared to DRAM, making it particularly useful in applications like CPU caches where speed is critical. However, it generally comes at a higher cost and uses more space on a chip than DRAM. This characteristic of not needing refreshing simplifies its operation in certain applications, as it can immediately provide stored data when accessed, enhancing overall performance in specific scenarios.

The other choices present characteristics that do not apply to SRAM. For instance, the notion of losing data when power is turned off corresponds to volatile memory types, which do not apply here since SRAM retains data while powered. Similarly, the requirement for periodic refreshing is a defining characteristic of DRAM, not SRAM, and while SRAM can operate at various