Using principle of locality to improve performance while keeping the memory system affordable we can pose four questions about any level of memory hierarchy. We will answer those questions considering one level of memory hierarchy.

  Block Placement
            Where should a block be placed in the cache?

  Block Identification
            How is a block found if it is in the cache?

  Block Replacement
            Which block frame in the cache should be replaced upon a miss?

  Interaction Policies with Main Memory
            What happens on reads and writes to the cache ?