Hive Power is the Hive Token locked up in a Smart Contract where it is not tradeable or saleable.
Emphasis on the word Power, Hive Power is symbolizing how much influence you have inside the Hive platform. Influence here is the same as value or amount of Hive you award with your upvote or approval vote on content posted here.
If you have a lot of HIve Power your upvotes will count more. An important point to make at this point is that your upvote awards Hive tokens from a pool of Hive called the Reward Pool which is regenerated daily. These Hive rewards don’t come from your wallet.
If you want to convert back from Hive Power to the base currency of Hive, it will be converted within 13 weekly conversions. These weekly payments are made directly to your HIve wallet.