Without this it can be assumed that a game doesn't automatically restore from any point if there are no lives: shows game over screen and possibly some options like load last save, return to main menu, restart level, or some such. Effectively these are checkpoints or similar that don't create a permanent save.

With lives tag present we can assume this means mid-level retry points (without this retry would be at level start).

The game may or may not inform you of reaching such points.

These are NOT the same as save points, but commonly these also function as save points.

By default we can assume that the game world is not changed at all when you die and are returned to such point.