When your computer-loving friend takes your photograph, you might be wise to ask, "Are you planning to put that on your blog?" A blog is a personal website or online journal.
It seems like everyone has a blog these days, or a website that's used as a personal diary for posting photos, stories, and entries about interests, families, or hobbies. Blog can also be used as a verb to mean "post something on a blog," so you could say, "I plan to blog about how delicious this slice of apple pie tastes." The original term, which was first used in the mid-1990s, was weblog, which was shortened to blog by 1998.