Difference between a blog and a wiki

Truthfully I am not sure I know the difference.  The DISD Library Media Services uses a wiki for Q and A. A select few upload questions and a different group answer. That is extent of my knowledge of wikis. I have never blogged until now. Being a resource person I went to the web to find my answer. At Ask.com I was sent to an article that gave this list:
Wiki:

- Multiple Authors,
- Edited by a group or team,
- Contains links to other Wiki pages,
- Continuously changing and growing rapidly,
- Many-to-many communication.

Blogs:

- Usually a single author. Sometimes can have multiple contributors,
- Author posts, user comments,
- Opinion Sharing ,
- One-to-many content.


This helps but I am still a little nervous that I don't know enough. That would be a good reason I need to take the Seven Things Web 2.0 class.

Information found at the site listed below:
Answers.com
http://wiki.answers.com/Q/What_are_the_differences_between_a_blog_and_a_wiki&alreadyAsked=1&rtitle=Is_wiki_answer_a_blog