A weblog or blog (derived from web + log) is a web-based publication consisting primarily of periodic articles (normally, but not always, in reverse chronological order). Although most early blogs were manually updated, tools to automate the maintenance of such sites made them accessible to a much larger population, and the use of some sort of browser-based software is now a typical aspect of "blogging."
Blogs range in scope from individual diaries to arms of political campaigns, media programs, and corporations. They range in scale from the writings of one occasional author (known as a blogger), to the collaboration of a large community of writers. Many weblogs enable visitors to leave public comments, which can lead to a community of readers centered around the blog; others are non-interactive. The totality of weblogs or blog-related websites is often called the blogosphere. When a large amount of activity, information and opinion erupts around a particular subject or controversy in the blogosphere, it is sometimes called a blogstorm or blog swarm.
The tools for editing, organizing, and publishing weblogs are variously referred to as "content management systems," "publishing platforms," "weblog software," and simply "blogware."