Hi,

I am a little confused about how changelly gives us the ability to buy bitcoins without an ID? Does this mean they are using someone like localbitcoins?
Howcome they dont need any id to buy and sell BTC? Are their rates much higher? Why does almost everyone use bitfinex to trade bitcoins and not something like changelly? In other words what does changelly actually do?

https://changelly.com/faq - I am referring to this .