A wiki is a Web site that can be viewed and modified by using a Web browser. Thus anybody visiting the wiki can change its content whenever he or she wants. Wikis are collaborative group sites. Wikis permit communication and group collaboration across the web. Described as a composition system, a discussion platform, a host site, a mailing system, and a tool for collaboration, wikis give users with both author an editor privileges; the whole organization of contributions and the content can be edited. Wikis can incorporate audio, movies, and images; It is a good way to create multimedia presentations and digital stories. What makes a wiki different from a blog is that many people can work on the same topic or content. This is, a single article could have as many authors as many hundreds of readers. It is quite different from a blog where an article will usually be written by only one author. Some blogs are the efforts of multiple bloggers, nevertheless, a single piece of content is generally attributed to a single blogger. In some cases, an editor could review the article to make some observation, but it usually doesn't make much difference. It is the collaborative effort that makes wikis so great.
As far as the implications for teaching and learning, wikis could be the easiest and most effective Web-based collaboration tool in any instructional portfolio. They give students direct and immediate access to a site’s content. This is crucial in group editing or other project activities. Wikis are often used as e-portfolios, showing their utility as a means for collection and reflection. Not only are wikis limited to students. Administrative and teaching staff can use wikis to collaborate on projects, editing a textbook, writing a journal article, or preparing a syllabus. Only one’s imagination and time can limit the possibilities to use wikis as the platform for collaborative projects.
In the following video you can see a short explanation of wikis and how they can be used to coordinate a group: