What is a Web Filter?

Content-control software, also known as censorware or web filtering software, is a term for software designed and optimized for controlling what content is permitted to a reader, especially when it is used to restrict material delivered over the Web.

Content-control software determines what content will be available on a particular machine or network; the motive is often to prevent persons from viewing content which the computer's owner(s) or other authorities may consider objectionable; when imposed without the consent of the user, content control can constitute censorship.

Common use cases of such software include parents who wish to limit what sites their children may view from home computers, schools performing the same function with regard to computers found at school, and employers restricting what content may be viewed by employees while on the job.

The web is a fast changing place and even large web search engines such as Google or Altavista or Yahoo don't even know of half of it. This makes filtering by web address (URL) difficult as sites change and new ones come up all the time. It is impossible to have comprehensive filtering using just URLs. What is needed is something to check every page you (or your children) ever access for 'bad' subjects such as drugs, profanities, hate, pornography, etc, and disallow it if it's not suitable. This is called 'Content Filtering'.