What Is a Wiki? Is It a Blog?
Wikis are websites collaboratively written by groups that seek to document and inform about a specific topic. Wikis can be private, open only to those in the group, or they can be publicly available (such as Wikipedia). Like blogs, wikis include comments and allow links, images, and video.
However there are some differences both structurally and functionally between blogs and wikis. Blogs are usually linearly arranged so that the most recent posts show at the top of the page, with archive links off to the side. Wikis are organized as a series of pages arranged to suit the people maintaining the wiki; a front page usually introduces the content of the wiki and typically includes a search box. In blogs, only authors of the blog can add posts, and only administrators of the blog may change or delete those posts; viewers respond in comments. Most wikis, on the other hand, allow any user to add or remove any content so your contribution might be deleted or changed in some way. Most wiki software includes some type of history so you can track when and by whom changes were made and, if desired, revert to an earlier version. The best wikis are sprawling collections of information on a topic the writers are passionate about.