Blog is a combination of the terms web log and is a discussion of informational site published on the world wide web and consisting of discrete entries (posts) typically displayed in reverse chronological order with the most recent posts appearing first. A blog is your best bet for a voice among the online crowd. It's a personal website, packed with features, as easy to use as your e-mail.
Blogging is very popular today because it allows people to interact with each other. Blogging has also become a popular search engine optimization (SEO) tool because search engines like Google and Yahoo know that a blog is frequently updated with content or visitor comments, so their spiders visit blogs frequently looking for new content to include in their index.
Additionally, blog content can be delivered automatically via electronic RSS (Really Simple Syndication) data feeds. Visitors subscribe to a blog's feeds in order to stay up to date with content that's being posted on subjects that interest them. Blog feeds are then read by what's known as blog feed reader software, widely available for free, so users can scan for recent blog posts of interest on the blogs to which they subscribe.
Finally, blogging doesn't require that writers and contributors know a lot about HTML (Web page code). If a blogger or visitor can fill in an online form, they can blog and post comments on other blogs.