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.

Many blogs are personal, "what's on my mind" type musings. Others are collaborative efforts based on a specific topic or area of mutual interest. Some blogs are for play. Some are for work. Some are both.

Blogs are also excellent team/department/company/family communication tools. They help small groups communicate in a way that is simpler and easier to follow than email or discussion forums. Use a private blog on an intranet to allow team members to post related links, files, quotes, or commentary. Set up a family blog where relatives can share personal news. A blog can help keep everyone in the loop, promote cohesiveness and group culture, and provide an informal "voice" of a project or department to outsiders.