Saber provides liquidity for stablecoins, which are cryptocurrencies whose value is linked to another asset, such as the US dollar or bitcoin. Saber is Solana's major cross-chain liquidity network, allowing users to transfer assets between the Solana blockchain and other blockchains. Users deposit bitcoin into a Saber liquidity pool in exchange for passive revenue in the form of transaction fees, token-based incentives, and eventually automated DeFi methods.
More information on Saber can be found at the following link: https://medium.com/cryptobrosresearch/saber-the-leading-cross-chain-stablecoin-exchange-on-solana-47824fb661a1