Which type of memory is used first by the CPU to access data?

The correct answer is L1 Memory, which is the fastest type of cache memory located directly on the processor chip itself. It is designed to provide the CPU with the quickest possible access to frequently used data and instructions. When the CPU processes information, it first checks the L1 cache for the needed data because of its proximity to the CPU architecture, thereby minimizing latency and improving performance.

L1 cache is extremely small in size compared to L2 and L3 caches, but its speed is essential for the CPU's operation. If the data is not found in L1, the CPU then checks the L2 cache, followed by the L3 cache before ultimately having to access the much slower main system memory or virtual memory. This tiered approach allows for an optimized method of fetching data, prioritizing quicker cache accesses over slower main memory accesses.