Cache design refers to the architecture and organization of cache memory in a computer system. Cache memory is a smaller, faster type of memory that stores frequently accessed data and instructions to reduce the time taken to access them from slower main memory. Cache design focuses on optimizing the performance of the cache memory by determining the size, organization, replacement policies, and access patterns of the cache. This involves making decisions on the level of associativity, block size, and caching algorithm to use in order to maximize hit rates and minimize misses. Overall, cache design plays a crucial role in improving the efficiency and speed of a computer system by reducing the latency associated with accessing data from main memory. It is a key component in modern computer architecture and is constantly being researched and optimized to keep up with the demands of increasingly complex computing tasks.