Steem is explained as a fundamental unit of account on a platform called Steemit. Steemit is a Blockchain-based platform where users can publish content and vote on it like on every other social media platform, but with the difference that on Stemmit, they are rewarded with tokens.
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.