> For the complete documentation index, see [llms.txt](https://docs.altitude.fi/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.altitude.fi/general/yield-generation-process/what-is-a-vault.md).

# What is a vault?

The protocol uses a vault for each currency pair, each with a fixed supply asset and fixed borrow asset. The supply asset is the crypto asset users can deposit and use as collateral for a loan; the loan received will always be received in the borrow asset.