What is a weblog/blog? (blogger.com) A blog is a web page made up of usually short, frequently updated posts that are arranged chronologically-like a what's new page or a journal. The content and purposes of blogs varies greatly-from links and commentary about other web sites, to news about a company/person/idea, to diaries, photos, poetry, mini-essays, project updates, even fiction. Blog posts are like instant messages to the web.