blog, short for web log, an online, regularly updated journal or newsletter that is readily accessible to the general public by virtue of being posted on a website. Blogs typically report and comment on topics of interest to the author, and are usually written and posted using software specifically designed to facilitate blogging; they include hyperlinks to other websites and, often, photos, video clips, and the like. The most recent entry by the blogger is posted at the beginning of the blog, with earlier entries following in reverse chronological order; comments and other responses to the blog by readers are often posted after each entry.
Although some bloggers have (or have achieved) prominence and expertise that makes them as influential in politics and other areas as established journalists, reviewers, and critics (some of which maintain blogs themselves), many bloggers reach relatively few readers and discuss matters of largely personal interest. Blogs also have been used by politicians, businesses, and others to keep voters, customers, and the like informed on matters of common interest; they can function as a significant alternative to television, newspapers, and other mainstream media, especially in nations where the media are controlled or censored by the government. Bloggers have at times broken important news stories or marshalled public opinion on a matter of public interest.
Online journals first appeared in the early 1990s. The development in the late 1990s of software that made updating an online journal easier and the subsequent rise of websites that specialized in hosting blogs spurred the rapid growth of blogging in the first years of the 21st cent., and by the mid-2000s there were millions of blogs on the Internet. By the end of 2010, however, social networking services such as Facebook and microblogging services such as Twitter had superseded blogs in some areas.