A web filter is typically a software that basically controls what kind of content can be displayed on a computer, specially content that is sent through the Internet such as web pages, emails and so on. Also known as content control software or content filtering software, the software checks the content of the page or email, and may also check the origin of the data as well, to determine whether or not it can or should be displayed.
Most people have encountered web filters at their offices and workplaces, and many browsers today also include at least some basic web filtering capabilities as well. However, web filters can also be used by governments to restrict certain forms of Internet access. Examples of countries that use web filters include China, Cuba, France and even Germany, though each country has set their own level of web filtering. Even in the United States, there are cases of state-mandated web filtering in certain libraries and schools.
While generally considered restrictive when used by governments to control the flow of information into and out of a country, companies generally use web filters in order to improve the quality of work done by employees, while schools and educational institutions may use web filters to prevent access to illegal or questionable materials, and parents may use such to keep their children from viewing questionable sites and content over the Internet. Internet Service Providers may also provide a certain level of web filtering as well, typically to protect from malware, viruses and spyware.
So while some people view web filters in a less-than-positive light, they can actually be very effective tools to protect not only your business, but your home. From restricting access to questionable or non-productive websites and emails, to protecting you from threats transmitted online, web filters can be a very valuable tool for both companies and individuals as well.