I have read this sentence and can not get "does is" meaning. Which type of grammar is it?
Couchsurfing is a fairly new website, and what it does is it allows travelers from different parts of the world to meet people in the destinations they're going to. People offer a couch in their home or perhaps space on their floor, and in return you're expected in your own hometown to offer the same kind of things to people who might visit you.