Explaining How Steemit's three currencies work - Guide

The Steem token (STEEM): is the network's base token. It is traded on multiple cryptocurrency exchanges and markets. Its market value determines the value of the pool of rewards paid by Steem. Its value also backs the value of Steem Dollars.

Steem Dollars (SBD): are an asset intended to be pegged to the United States dollar. Steem Dollars can be traded at cryptocurrency exchanges, and used for payments for goods and services.

Steem Power (SP): is Steem that has been entered into a smart contract and represents the amount of influence an account has compared to the rest of the network. The more STEEM Power an account has, the higher influence its vote has on posts or comments. STEEM Power also determines an account's weight for witness approval voting.

Additional note: Steem Dollars which are held receive an interest rate. This rate is set as a variable collectively by Steem witnesses. This rate is often 0%, but it may fluctuate. If Steem Dollars are being traded below parity with the US dollar and the supply of Steem Dollars is not too high relative to the liquid STEEM supply, the interest rate may rise. explain how Steemit's three currencies work?