If the date of the cached file is the same as the original, then the cached copy is used. Web browsers normally maintain a cache of retrieved documents and this cache is used for retrievals where possible. In addition, the user may configure the browser to point to a caching server via the browser's options or preferences. File requests not able to be supplied from the browser cache would then be directed to the caching server. The caching server would supply the files from its cache if they were current, or pass on the request to the originating server if they were not.
Users employ client software, such as a Web browser, to request information from servers.
Servers, such as WWW servers, supply information in response to requests from clients. The client, which is normally installed on the user's computer, displays the information for the user. For instance when a Web document is retrieved from a remote server, the client will interpret the HTML tags and display the document appropriately. Some aspects of how documents are delivered and displayed may be determined by the user through configuration of the client's settings, for instance size and colour of font, whether images are displayed, whether cookies are accepted. Web browsers generally can use other Internet protocols as well.