Blog can be explained as a personal journal that can be published on the World Wide Web. These are either a one man's work, or a small group of people get together and write about something and put it up on the internet.
A blog is basically a type of website, like a forum or a social bookmarking site. It is not about the content published but about the technical aspects and features.
A typical blog combines text, images, and links to other blogs, Web pages, and other media related to its topic. Most good quality blogs are interactive, that allow visitors to leave comments and even message each other. Bloggers do not only produce content to post on their blogs but also build social relations with their readers and other bloggers. There are 3 kinds of Blogs, one provides commentary on a particular subject; second type is more a personal online memoir and the last one is used to advertise a brand online of a particular individual or company.