Content Filtering: -

On the Internet, content filtering (also known as information filtering) is the use of a program to screen and exclude from access or availability Web pages or e-mail that is deemed objectionable. Content filtering is used by corporations as part of Internet firewall computers Content filtering usually works by specifying character strings that, if matched, indicate undesirable content that is to be screened out. Content is typically screened for pornographic content and sometimes also for violence or hate oriented content. Content filtering and the products that offer this service can be divided into Web filtering, the screening of Web sites or pages, and e-mail filtering, the screening of e-mail for spam or other objectionable content.