Balancer is a decentralized exchange or DEX and automatic market maker or AMM with a very flexible toolset. Inverse Finance utilizes two different pool types:
One is the INV-DOLA pool with a 50/50 weighting between the assets.
The other is a DOLA-bb-a-USD pool with a 50/50 weighting. Bb-a-USD is an innovative use of composability as the bb--a-USD token holds (close to) equal parts USDC, USDT and DAI. A proportion of each of the USDC, USDT and DAI in the bb-a-USD pool are deposited in Aave Finance to obtain yield and make the token intrinsicly productive.
When depositing liquidity to Balancer, you will receive a Balancer LP token in return. This LP token is what proves your stake in the liquidity pool and you need it to withdraw your funds. Trading fees accumulated to the liquidity providers are added your balance automatically and BAL or AURA incentives are claimed on Balancer's website.