Did you just get married (and change your name)? Congratulations!
One aspect of getting married (or otherwise changing your name) is to get a renewed Passport to reflect your new name change. You do not need to get a New Passport (which is more expensive and requires more steps, including going to a Passport Acceptance Agent) just to change your name - you can Renew Your Passport and have your Passport Name changed at the same time - a much easier process than getting a full New Passport