You must have heard about Wikipedia—the immensely popular online encyclopaedia which contains detailed information about millions of things—people, places, products, features, science, technology, etc. A large number of people who are in the habit of visiting Wikipedia to seek information may find themselves confused with similar sounding terms like Wiki, Wikimedia, Media Wiki, etc.
To avoid confusion and to get a better hand of what these words imply or represent, we shall in the subsequent paragraphs discuss the differences between all these.
Wiki— a wiki is a type of website which allows you the freedom and flexibility to edit contents from the web browser. It keeps a version history of each edited page.
Wikimedia-- Interrelated projects related to the Wikipedia Movement like Wikipedia, Wiktionary, Wikiquote, etc are collectively referred to as Wikimedia.
Wikipedia-- it is a Wikimedia project that is a global, free and multilingual internet encyclopaedia.
Media Wiki is free open-source server-based Wiki software, licensed under the GNU General Public License (GPL). Similar to any other wikis, it allows common users who lack technical expertise and proficiency in web designing languages like CSS and HTML to create and edit web pages content. The real beauty of it lies in the fact that it allows anybody and everybody to edit the content but maintains a history of it in its database so that the integrity of the articles and posts can be maintained. This allows for easy reverts if there happens to be a case of vandalism, spamming or other mischievous activities on the part of the users.
Media Wiki is incredibly powerful, feature-rich, scalable and reliable software which uses PHP programming language to process and display data stored in a database. One word of caution though is that like any other software on the net, Media Wiki is also prone to malicious viruses and security threats. It is therefore important to keep up with latest security updates when you install it.