A web filtering program is what is known as a WAF in computer lingo.
It is designed to block or remove web pages that may be considered inappropriate for viewing by a particular age group, gender, language, and other descriptors.
In other words, a web filtering program prevents certain material from being viewed on the Internet.
Often times web sites are created that cater to certain interests or are based around a particular religion, the style of music, film, or hobby.
A web filtering program is a special type of program that filters, guards, and controls all HTTP traffic that comes into and leaves an IP-based system.
This includes all information sent and received by any application on any web server, including both text and multimedia packets.