Tags are a great and easy way to create lists of titles on the fly. You and your staff are able to collaborate on Tags, making it an easy team effort.
The Notes option is where you can attach your own notes to a title. This gives you an area to write something specific about a title and in greater detail than a tag. By default, your colleagues will be able to see these notes, and you also may optionally share these with your rep by making particular notes visible to them.