The blog is short for "web log" is a form of web applications that resemble the writings (published as posts) in public web pages.
These writings are often published in reverse order (the latest content first and then followed the older content), although not always the case.
Web sites like this can usually be accessed by all Internet users according to topic and purpose of the user's blog.

1.Blogger community
Community bloggers is a bond that is formed from [the bloggers] on the basis of certain similarities, such as the common origin, common campus, similar hobbies, and so forth. The bloggers who are members of communities of bloggers are usually often holding activities together such as ground coffee. To be able to join the community of bloggers, usually some sort of terms or rules that must be met in order to enter the community, ie, originating from a particular region.
2. Types Of Blog
a. Political Blog: About the news, politics, activist, and all the issues-based blogs (like the campaign).
b. Blogs Personal: Also called an online diary which contained about someone everyday experiences, complaints, poems or poetry, bad ideas, and conversations of friends.
c. Blogs stubs: Blog which discusses something, and focuses on a particular discussion.
d. Blogs health: To be more specific about health. Health blog mostly about the patients' complaints, the latest health news, information about health, etc..
e. Blogs literature: Better known as lit blog (Literary blog).
f. Blogs trip: Focus on the discussion of travel stories that tell the details about the trip/travel.
g. Blog of research: The question of academic as the latest research news.
h. Blogs law: The question of law or legal affairs.
i. Blogs Media: Focusing on the discussion lies or not same as media, usually only for a newspaper or television network
j. Blogs religion: To discuss religion
k. Blog of education: Usually written by students or teachers.
l. Blog of togetherness: more specific topics written by a particular group.
m. Blogs instructions (directory): Contains hundreds of links pages.
n. Blog business: Used by employees or entrepreneurs for their business promotion activities
o. Blogs embodiments: Focus on an object outside of human beings.
p. Blogs disruptors (spam) 

3. Risk of crime
Because blogs are often used to write everyday activities that occur on the author, or reflecting the views of its author about a variety of topics that happen and to share information - blogs a source of information for hackers, identity thieves, spies, etc. Many secret files and sensitive issues found in the writing of blogs. This lead to a person fired from his job blocked access, fined, and even arrested.

Okay, friends... That's all info for blog :)