Fandom Wikia

Fandom Wikia (formerly Wikicities) is a free web hosting service for wikis (or wiki farm). It is normally free of charge for readers and editors, deriving most of its income from advertising, and publishes all user-provided text under copyleft licenses. Wikia hosts several hundred thousand wikis using the open-source wiki software MediaWiki.

Wikia definition - Wikipedia

Tutorial
How to make your first wiki on Wikia

What is a wiki
A wiki (/ˈ w ɪ k iː /  WIK  -ee) is a website which allows its users to add, modify, or delete its content via a web browser usually using a simplified markup language or a rich-text editor. Wikis are powered by wiki software. Most are created collaboratively.

Wikis serve many different purposes, such as knowledge management and notetaking. Wikis can be community websites and intranets, for example. Some permit control over different functions (levels of access). For example, editing rights may permit changing, adding or removing material. Others may permit access without enforcing access control. Other rules may also be imposed to organize content.

Wiki definition - Wikipedia