A cache is a repository for stored data that is used to expedite the process of retrieving data. There are several types of caches, including webpage caches, hardware caches, software caches and memory caches. Caches are used to speed up a process so that data does not have to be recomputed or fetched from its original location and, therefore, saves time. The greater the requests that can be served from the cache, the quicker system performance becomes. A cache hit is when a program checks the cache for previously stored information and finds it. A cache miss is when the data is not found within the cache and the program must look to a larger, slower memory source. Computers can have several caches: the L1 cache is built into the computer processor’s chip, the L2 cache is built onto the motherboard and the L3 cache is just the L2 cache on a computer that has two caches built into the microprocessor.
Internet browsers use caching to store HTML web pages by storing a copy of visited pages and then using that copy to render when you re-visit that page. If the date on the page is the same date as the previously stored copy, then the computer uses the one on your hard drive rather than re-downloading it from the internet.
To learn how to clear your cache, click here.