what is blog.....

A blog—a shorthand term that means “Web log”—is an online, chronological collection of personal commentary and links. Easy to create and use from anywhere with an Internet connection, blogs are a form of Internet publishing that has become an established communications tool. Blogging has evolved from its origins as a medium for the online publication of personal diaries to a respected vehicle for editorials on specific topics. In their latest incarnation, blogs represent an alternative to mainstream media publications. The personal perspectives presented on blogs often lead to discourse between bloggers, and many blog circles generate a strong sense of community.
http://net.educause.edu/ir/library/pdf/ELI7006.pdf