A wiki is typically a website containing webpages of relevant information (such as soccer team on a soccer wiki). These webpages are usually editable by anyone, so multiple people can contribute to adding and correcting information on the wiki. Most wikis have a number of safeguards against malicious users, such as account-only edits, IP-bans, reverting the page to a previous edit, and more.
Wikis and blogs share a similarity, but their overall purposes are quite different. Both allow one or more people to post and edit information (yes, some blogs allow multiple users to post and edit the same blog).
On one hand, wikis are usually unbiased, factual, focused on a specific topic (with the exception of wikipedia or similar wikis), and their webpages are designed to be searched. The rules each blog follows are determined by the blogger. Their posts can be biased, opinionated, and focused on a variety of topics. They are usually designed so that the most recent post is shown, with older ones located through archive links. However, bloggers have more freedom to post what they want, not having to adhere to wiki guidelines.
Wikis have notable advantages over blogs. One can find more information collected by a large number of editors on wikis compared to the one or few bloggers on the same topic. The quality of said information is usually better in wikis as well, compared to posts in blogs that become more and more outdated over time.
Two examples of education-based wikis are Factorywall and ABC Learning Resources Centre. The home page hosts numerous links to different pages of related information. The wikis are fairly organized, although the layouts could use some work. Those two wikis are good examples of the kind of wikis you may find online.
