Temporarily storing items (for example HTML, CSS JavaScript and multimedia files) retrieved from a server on a local hard drive so they can then be accessed locally rather than having be to requested and downloaded again from the server.
Since retrieval from a local drive is much faster than access via a network, this greatly improves the responsiveness of web pages.
When viewing a recently updated web page that you have visited previously, it may be necessary to refresh the page in your browser or clear your browser cache in order to view the new content.
Other caching techniques include:
Pre-caching: Retrieving and storing files before they are actually called from the page
Server Caching: Web developers often cache dynamically created pages on a server so that they may be delivered to users without the page having to be reassembled. This reduces the load on the server as well as speeding the delivery of content.
Content Delivery Network (CDN): Caches resources such as multi-media or dynamically generated pages on a network of servers so that the content can be delivered most efficiently based upon the user’s location.