As professional wrestling seeks to also tell a story, some matches are made solely for the purposes of advancing the plot. This typically involves the loser of a match being penalized in some way.
Loser Leaves Town match
Loser Leaves Town is a generic term for any match where the loser has to leave the current promotion or brand. These matches were most often held during the "territorial days", when wrestlers frequently jumped from company to company.
A Retirement match is any match where, should a wrestler lose, they are forced out of the company. The "retirement" stipulation can be applied to just one wrestler or both wrestlers in a match can be wrestling for their careers. Further still is a more legitimate retirement match, the last match of a (usually "legendary") wrestler's career. In this case it's designed to be a last hurrah, showcasing the wrestler's talent one last time for their fans.