Steem Dollars can be sent to an exchange (ex: Bittrex), then exchanged to BTC, which then can be exchanged for STEEM. Steem Dollars are a separate trade-able unit, and can, but do not have to be used on the Steemit Site.
You can buy just about anything with Steem Dollars, as long as the seller will accept them. Otherwise, going through an exchange like Bittrex will allow you to convert them into an acceptable crypto. Hope this helps! Let me know if I can clarify further.
That helped :) Thanks bro
Coinbase will put BTC, LTC, BCH OR ETH right into yo bank account as cash deposit.
You have to send to there first. 2.99% fee I think.