Boost Maker vault is a strategy to increase the exposure of a vault collaterals. Some calls this strategy “Leveraged CDP”, “Boost Vault Exposure”, “Increase Vault Exposure”, etc. Just think of this strategy as boosting both your collateral and your debt at the same time. When your collateral increases, you get to generate more DAI. Then you use those DAI to buy more collateral and send back to your vault. Your collateral increases again! So you generate more DAI again, buy more collateral… and repeat. Overall, the approach is to multiply the exposure of the collateral asset to profit from price surges without any upfront capitals.