- A blog is normally a single page of entries. There may be archives of older entries, but the "main page" of a blog is all anyone really cares about.
- A blog is organized in reverse-chronological order, from most recent entry to least recent.
- A blog is normally public -- the whole world can see it.
- The entries in a blog usually come from a single author.
- The entries in a blog are usually stream-of-consciousness. There is no particular order to them. For example, if I see a good link, I can throw it in the blog. The tools that most bloggers use make it incredibly easy to add entries to a blog any time they feel like it.