1. Obsidian makes use of a local folder of Markdown text files, rather than syncing to a cloud database like Roam.

2. Each page in Roam is an outline (as in outliner), whereas each file in Obsidian is a Markdown file.

3. #tag is not the same as [[tag]] in Obsidian.

4. Rather than a built-in feature, "daily notes" is available as a plugin in Obsidian.