Can someone please explain Roleplay sites to me?

Basically what te do in a roleplay is te create o claim a character and te portray him/her. te have conversations with other characters, etc. At least that's how most roleplays go...
i recently just started my own Supernatural roleplay if you're interested in joining, we'd be happy to have te :)
www.supernaturalroleplay.piczo.com
yeah i checked out the site te signed up for and it seemed pretty confusing..
but mine is a LOT simpler to follow in case you're wondering :)