Steem Backed Dollars are there to protect content creators from volatility and can be traded for roughly 1 usd worth of steem, in order to cash out from steem. Converting Steem backed dollars into STEEM takes 5 days. Users also recieve interest from holding SBD.
Underneath the hood of Steemit.com there is a tradeable cryptocurrency token, called Steem, and it’s performing well on the US-based exchange, bittrex.com, and blockchain-based exchange openledger.info. With Steemit.com, posts, comments and votes are immutable. Attribution is a given. Accreditation is not taken for granted. And community appreciation is an actual reward.