Explain what a level 3 cache in computer architecture is.

Level 3 cache (L3) is the last level of cache memory in the processor hierarchy, which is usually shared among multiple cores. It is larger and slower than the Level 1 (L1) and Level 2 (L2) caches, but faster than the main RAM. The L3 cache is used to store frequently accessed data and instructions to speed up access for all processor cores, reducing latency and increasing overall system performance.