Cryptocurrencies

would be nice if you could say a few words why. The Ledger Nano S as wallet is pretty straightforward, there are only 3 options and any is good. But why Coinbase for deposit and why Binance to trade? What is Binance anyway, on their site it looks like they have their own currency. Is there no good exchange where you can do everything? Transferring coins between exchanges seems like a lot of hassle. So what, first you send dollars to coinbase, then exchange to eth, then send to binance, then exchange to, say, iota, then transfer to ledger nano?

Maybe one side question: how do exchanges fix a price? I understand they find a matching pair of buyer and seller, but in the end they need to add this to the blockchain. So you fix a price and then you wait a couple of hours to see if it went through? Are the exchanges miners themselves?