Staking is a mechanism in which validators commit cryptocurrency to secure blockchains, and restaking protocols like Symbiotic allow that stake to be reused across multiple blockchains.

Quotes that support claims

Staking is a system for securing blockchains in exchange for rewards. In staking systems, so-called validators commit callateral — called "stake" — for a role in processing transactions. "Restaking" protocols like Symbiotic let users reuse stake across multiple blockchains at once, offering investors the opportunity to earn extra yield.