Microblogging is a passive broadcast medium in the form of blogging. A microblog differs from a traditional blog in that its content is typically much smaller, in both actual size and aggregate file size. A microblog entry could consist of nothing but a short sentence fragment, an image or embedded video.

As with traditional blogging, microbloggers post about topics ranging from the simple, such as "what I'm doing right now," to the thematic, such as "sports cars." Commercial microblogs also exist, to promote websites, services and/or products, and to promote collaboration within an organisation.

Some microblogging services offer features such as privacy settings, which allow users to control who can read their microblogs, or alternative ways of publishing entries besides the web-based interface. These may include text messaging, instant messaging, E-mail, or digital audio.