A blog vs. a wiki

The blog owner writes and publishes their stories or posts and has full control over the blog content. Blog readers can only comment on the posts. They can not edit blog content. What's good for a blog -- library news, new resource updates, and library services. A wiki allows users to easily create and edit content. Wikis are often used for group collaboration and everyone can contribute. What's good for a wiki - subject guides, e-profiles, department notebook, etc.