The Steem network gives new Steem units to publishers and voters every day. Steem can be exchanged either on Steem Power (SP) or Steem Backed Dollars (SPD). Steem Power is a token used to upvote content, which helps to get a revenue both for a voter (in SP) and for a publisher in (SPD) proportionate to how much Steem Power the voter has. Steem Powered Dollars represent an amount of Steem equal to 1 USD. SMD helps to protect content creators from the volatility of the Steem cryptocurrency by promising them that they’ll get a fixed amount of money, no matter how much Steem will cost when they cash out.