This can lead into various other actions, such as using a regular grab (rather than dash grabs, which are poor compared to other grabs) out of a dash, or simply protecting the character as they move forward. It can also be used to stop the dash in order to perform attacks such as tilts and forward smashes, and can be canceled into a roll or sidestep (the latter which conserves forward momentum for most characters) to play mindgames with opponents; in Melee, however, canceling the dash with a crouch is a more common alternative for the former purpose due to shield drops taking longer to act out of in said game. As with other slide techniques, the overall movement gained by shield-stopping is dependent on one's traction.
Shield-stopping is not the same as a dashing shield. Dashing shields involve tapping the shield button and releasing it to gain distance, whilst the shield-stop is used as a regular shield out of dash.