A blog is a truncation of the expression weblog. Blogs, or Web logs, are online journals on different issues and are updated frequently, sometimes it may be number of times in a day. An update is an entry or a post. Blog articles are usually quite short and readers can respond to an entry online. People who write blogs are commonly called bloggers.
A majority of blogs are interactive where visitors can leave comments and even message. Blogging is not only a tool for sharing knowledge, it also build social relations among readers and other bloggers.
Blogs may be of different types. Many blogs provide commentary on a particular subject; others function as more personal online diaries; others function more as online brand advertising of a particular individual or company. A typical blog combines text, images, and links to other blogs, Web pages, and other media related to its topic.