Lists and tags can both be used to more easily find records, but here is the difference between them:
Lists: Each record that's manually imported into Invelo or saved from List Builder must be added to at least one list. Lists organize records by a specific category. For example, you may have a Driving for Dollars list, Absentee Owners list, etc.
Tags: Tags are optional keywords that you can add to any record to help group similar records.