Caching - Defination
Caching (pronounced “cashing”) is the process of storing data in a cache.
A cache is a temporary storage area. For example, the files you automatically request by looking at a Web page are stored on your hard disk in a cache subdirectory under the directory for your browser. When you return to a page you've recently looked at, the browser can get those files from the cache rather than the original server, saving you time and saving the network the burden of additional traffic.