Storing a copy of frequently accessed information in a fast medium for improved performance. A typical example is a web browser's cache. Whenever you visit a web page your browser checks if you visited that web page before, and if it finds you did, it then checks whether the files needed for viewing that particular web page was previously stored in its cache. If the answer is positive, then your browser will read the files from its cache without downloading them again from the remote server, and therefore the web page will come faster since hard disks are almost always faster than Internet connections.