Blogs (A contraction of "web log") are online websites where people write about their lives, or about issues that they find important. A Blogger can either be paid to blog, or can just be an amature who enjoys writing.
Types of Blogs:Edit
A single blog is a normal blog written by one person. (For an example: click here)
A multi blog is a blog written by multiple people.
Microblogging is where people send short messages of text or media. Usually one sentence of "What I'm doing right now." (Example: facebook status updates.)