A blog (a truncation of the expression weblog) is a discussion or informational site published on the World Wide Web and consisting of discrete entries typically displayed in reverse chronological order (the most recent post appears first). Many blogs provide commentary on a particular subject 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. The ability of readers to leave comments in an interactive format is an important contribution to the popularity of many blogs. Blogging sites can be done in joomla and word press also.