50 Shades of Grey...

I have been really into the books and movies and the Dom/sub relationship has made me want to not do it but learn about it more.. I'm just so curious to know about a real dom/sub relationship... Idk if I'm pushing boundaries but if anyone on here has had/is in a dom/sub relationship could you explain more about it... I feel the movie and book kinda didn't really portray a dom/sub relationship because they fell in love (sorry spoiler if you haven't read the books)