Datavälimuistiin

Datavälimuistiin, often referred to as data cache in English, is a temporary storage area used by computer systems to speed up access to frequently used data. It is a form of memory that is faster and smaller than the main memory (RAM). When a program needs to access data, the system first checks the datavälimuistiin. If the data is found there, it is retrieved very quickly, which is known as a cache hit. If the data is not in the datavälimuistiin, the system retrieves it from the main memory or storage, and then copies it into the datavälimuistiin for future use. This process of copying data into the cache is called a cache miss.

The effectiveness of a datavälimuistiin depends on the principle of locality, which states that programs tend to access the same data or nearby data repeatedly. There are two types of locality: temporal locality, where data used recently is likely to be used again soon, and spatial locality, where data located near recently accessed data is likely to be accessed soon. By storing frequently accessed data in the fast datavälimuistiin, the overall performance of the computer system can be significantly improved, as it reduces the time spent waiting for slower memory accesses. This is a fundamental concept in computer architecture and is employed at various levels, from CPU caches to disk caches.