What is the main purpose of the CPU cache?

• A. Store frequently accessed data temporarily
• B. Permanently store data
• C. Increase data access speed by caching recently used data
• D. Provide power management for CPU

Answer: (C)

The main idea is that the CPU cache is a small, very fast memory close to the processor that holds copies of data from main memory that the CPU is likely to need soon. The job of this cache is to speed up data access. When the CPU needs information, it first looks in the cache; if the data is there (a cache hit), it can be retrieved quickly instead of waiting for slower RAM. This speed boost comes from locality of reference: recently used data tends to be used again soon, and nearby data is likely to be used next, so keeping those items ready in the cache reduces waiting time. It isn’t meant for permanent storage or power management—those are handled by other parts of the system.