A content partner is a paysite owner that works with the tube site (it can be XHamster), so he will upload his content aka videos to their site and he will be able to promote his paysite on this website. So an example of a content partner is this channel: xhamster.com/users/passion-hd.

Of course, you will need your own exclusive content and a paysite to be able to become a content partner.

An adult webmaster is a person that owns an adult site so if you have created a website, it can be a tube site, blog, review website, forum), you are a webmaster.