A web cache is a mechanism for the temporary storage (caching) of web documents, such as HTML pages and images to reduce bandwidth usage, server load, and perceived lag. A web cache stores copies of documents passing through it; subsequent requests may be satisfied from the cache if certain conditions are met. Web caches can be used in various systems.

A search engine may cache a website. b.

A network-aware forward cache is just caches heavily accessed items. c.

A reverse cache sits in front of one or more Web servers and web applications, accelerating requests from the Internet.

A client, such as a proxy browser, can store web content for reuse. For example, if the back button is pressed, the local cached version of a page may be displayed instead of a new request being sent to the web server.

The proxy browser is a sitting between the client and the server can evaluate HTTP headers and choose to store web content.

A content delivery network can retain copies of web content at various points throughout a network. There are two main reasons for use of Web caches: a.

To reduce latency - as the request is satisfied from the cache (which is closer to the client) instead of the origin server, it takes less time for it to get the representation and display it. This makes the Web seem more responsive. b.

To reduce network traffic - as representations are reused, it reduces the amount of bandwidth used by a client. This saves money if the client is paying for traffic, and keeps their bandwidth requirements lower and more manageable