A ratings ballot is a ballot on which candidates are rated on a cardinal scale. For example, candidates in an election could be rated from 0 to 99 or from -5 to 5 or from 1 to 10. Generally you will gave the candidate you like least the lowest score (0, -5 or 1) and the candidate you like the most the highest score (99, 5 or 10).
An Approval Voting ballot can be considered as a ratings ballot with two possible ratings 1 (approve) and 0 (disapprove). Under conditions of strategy (rational voters wishing to obtain the best outcome for themselves with perfect knowledge of how all other voters will vote) a rating ballot with more than 2 rating points should become identical to an Approval ballot with all candidates being given either the highest or lowest rating.
Ratings ballots can be converted to preferential ballots.
This requires the voting system to accommodate a voter's indifference between two candidates (as in Ranked Pairs or Schulze method).