Which type of memory is fast and located inside the CPU?

Cache memory is a small amount of high-speed memory located directly inside the CPU (or very close to it on the motherboard) that is used to temporarily store frequently accessed data and instructions. This memory enables the CPU to access data more quickly than it would if it had to retrieve it from the main RAM (Random Access Memory), which is slower in comparison.

The primary function of cache memory is to reduce the time it takes to access data and improve overall system performance. It works by storing copies of the most used data from the RAM, allowing the CPU to retrieve this data with much lower latency.

In addition to cache memory, there are other types of memory mentioned. RAM is crucial for active processes but is located outside the CPU and is generally slower than cache memory. Secondary storage refers to non-volatile memory such as hard drives or SSDs, which is significantly slower than both cache and RAM and used for long-term data storage. Virtual memory is a process that uses disk space to extend RAM capacity but does not relate to the physical memory within the CPU. Thus, cache memory stands out as the type of memory that is both fast and integral to improving CPU performance.