LiveJournal, stylised as LiVEJOURNAL, is a Russian-owned social networking service where users can keep a blog, journal, or diary. American programmer Brad Fitzpatrick started LiveJournal on April 15, 1999, as a way of keeping his high school friends updated on his activities. In January 2005, American blogging software company Six Apart purchased Danga Interactive, the company that operated LiveJournal, from Fitzpatrick.

A blog is an informational website consisting of discrete, often informal diary-style text entries (posts). Posts are typically displayed in reverse chronological order so that the most recent post appears first, at the top of the web page. In the 2000s, blogs were often the work of a single individual, occasionally of a small group, and often covered a single subject or topic. In the 2010s, "multi-author blogs" (MABs) emerged, featuring the writing of multiple authors and sometimes professionally edited. MABs from newspapers, other media outlets, universities, think tanks, advocacy groups, and similar institutions account for an increasing quantity of blog traffic. The rise of Twitter and other "microblogging" systems helps integrate MABs and single-author blogs into the news media. Blog can also be used as a verb, meaning to maintain or add content to a blog.