BNT stands for Bancor Network Token, and it powers a robust DeFi protocol for staking and lending. Since Bancor pools reward users for liquidity provision in proportion to their commitment, BNT supply is elastic, employing mint and burn to balance the supply and demand. The rewards come from trading fees made with the help of Bancor liquidity pools.
To prevent impermanent loss caused by an AMM balancing the value of assets in a liquidity pool, Bancor makes it so that a liquidity provider needs to commit only one asset to receive rewards from a pool.
In addition to yield farming, you can use BNT to participate in the Bancor DAO by voting on improvement proposals. Each token represents a vote, and the more you have, the more weight there will be to your votes.