What does having a watermark and copyright on photos mean for my wedding photos?

Hi there a photographer is an expensive part of our wedding day, and I have heard of some horror stories of couples having watermarks on their photos and having to pay extra to use their photos so after the day (i.e. to print and put on the wall or share to personal socials? Is that normal or expected i am a bit scared of all photographers and the legal stuff! Thanks Bree