Final answer:
A website that allows users to add, edit, or delete pages of content is known as a Wiki, which is a collaborative platform famously exemplified by Wikipedia.
Step-by-step explanation:
A website that allows anyone to add, edit, or delete pages of content is known as a (a) Wiki. This type of website is highly collaborative and allows for the community to contribute and modify information. One of the most famous examples of a wiki is Wikipedia, which is essentially an extensive online encyclopedia written and maintained by volunteers around the world in a multitude of languages. Unlike online forums where users can post and respond to messages, or Usenet which is a system of Internet discussion groups, a Wiki is unique in its collaborative editing capabilities. Furthermore, a lurker site typically refers to a website where many users read content but do not contribute. Therefore, the correct answer to this question is (a) Wiki.