can someone explain roleplaying blogs to me? 

I tried to look at them and see what was up but I don’t get where the people role-play, like where do they go??? 

And then they fill up the characters, but it doesn’t seem like they role-play on the blog?? Do they go to a set aside chatroom?? How does it work, do they type their big paragraph and then someone reblogs it???

Just someone explain this whole process to me.