Steem is a cryptocurrency that was released in 2016. It can be traded on the open market through cryptocurrency exchanges and obtained in exchange for goods or services. The price is very volatile due to the limited amount that's available on the markets. It's not very liquid and relatively small trades can move the price. Steemit does allows for mining, even though it’s not the primary way to earn money. Units can be bought or sold against other cryptocurrencies.
Steem has 3 distinct units:
-Steem, which can be bought and sold in the market
-Steem Power, which cannot be sold for 2 years
-Steem Dollar, which can be converted into Steem or Steem Power
Steemit is a social platform which attracts people that learn to use Steem naturally. The cryptocurrency has no cap on the number of units, as opposed to Bitcoin and Litecoin.