What happens when information requested by a CPU is not in cache memory?

When a CPU requests information, it first checks the cache memory to see if the data is available. If the requested information is not found in the cache—a situation often referred to as a cache miss—the CPU must retrieve the required data from the main memory.1

Because the cache is designed to store only the most frequently used instructions and data to speed up processing, relying on main memory when a miss occurs is a necessary step to ensure the processor receives the correct information, albeit at a slower speed than a cache hit.1