- noun a small area of high-speed static RAM fitted to a processor chip that stores frequently used data to improve processing speed
- A memory cache that is built right into the CPU. This contrasts with an L2 cache, which utilizes a memory bank between the CPU and main memory. L1 cache is faster, but smaller than L2 cache, while L2 cache is still faster than the main memory. Also called level 1 cache, internal cache, on-chip cache, first-level cache, or primary cache.