What is the difference between a forum and a blog?

Forums are a place for a group of people to discuss certain issues or subjects. They are generally more community oriented, providing a place for a community to get together and discuss/debate subjects of interest. Everyone is at an equal level, and users have high involvement with the topics they discuss. Many people can post their thoughts and discuss ideas.

A blog is more like a personal publishing system, or an online diary, and is more one-sided, with the blogger being in control of the discussion. It is usually one person who wants to make their opinions heard, and express themselves on the internet. They make posts about subjects of interest to them, and other people can read them and make a comment. But the original thoughts all come from the one person.