The word Blog is a shortening of the term web log and is a personal journal, published by a single person or a small group of people, where the theme for the articles is clearly defined.

The Blog articles are self-contained and are published on the World Wide Web as discrete posts that are usually displayed in reverse chronological order so the most recent post appears first. Blogs usually allow for simple user interaction where members or visitors can add comments against previous posts.

The purpose of a blog Blogs can be provide

• commentary on a particular subject;
• a personal online diary;
• an online brand advertising of a particular individual or company.

Typically, a Blog combines text, images, and links to other blogs, Web pages, and other media related to its topic.

Blogging is the act of entering data or comments onto a Blog. This is a form of social networking in that  bloggers do not only produce content on their blogs but also build social relations with their readers and other bloggers.

Blogs can be important for internet marketing and search engine optimization (SEO). A good Blog that provides novel and relevant content can become a vehicle for generating links to the Bloggers main website.

Technorati is considered to be the definitive Internet search engine used for searching Blogs.