A blog is a shortened fashion of the name weblog. It refers to an informational site or discussion on the World Wide Web consisting of distinct entries. The entries are characteristically presented in converse sequential order. At first blogs were used by individuals and often covered a single subject until recently when “multi-author blogs” (MABs) came into existence. The MABs have advanced with posts written by various authors and edited professionally. MABs from universities, advocacy groups, newspapers and other media outlets explain the intensifying of blog traffic. The emergence of microblogging systems like Twitter has helped in the integration of MABs and one person authored blogs into societal new streams. On the other hand, the word blog can be used as a verb to denote maintaining or addition of content to a blog.
Previously the knowledge of technologies like HTML was required for the publication of information on the web. The advent of blogs coincided with the emergence of web publishing tools and thus enhanced posting of information by non-technical users.
One thing that differentiates blogs from other fixed websites is its interactivity feature. It can be looked at as one form of social networking because of this feature. In spite of, some few blogs like Daring Fireball which have a vast readership do not allow comments most bloggers not only do they produce content to post on their blogs, but also build social relations with their other bloggers and readers.
Various blogs offer commentary on a specific subject; others work as more personal online diaries; others function more as online brand advertising of a particular individual or company. A typical blog combines images, text, and links to other blogs, other forms of media related to its field and Web pages. The expertise of readers leaving comments in an interactive format is an important contribution to the popularity of many blogs. Most blogs are primarily textual, although some focus on photoblogs, art, videos (video blogs or "vlogs"), audio (podcasts) and music (MP3 blogs). Microblogging is another form of blogging, featuring very small posts. Blogs can function as instructional resources in education. These type of blogs are termed as edublogs.