# Glossary ### sZERO sZERO is a non-transferrable ERC20 and represents a balance of staked ZERO, which is read from ZERO network nodes to determine voting weight, should the sZERO holder decide to run a validator. ### Signers Entities responsible for signing messages using the [FROST](#frost) protocol. ### Validators Entities responsible for producing blocks. ### Voters Entities holding a balance of staked ZERO (sZERO) on Ethereum mainnet, the on-chain governance token. ### Keepers Entities responsible for relaying transactions onto any supported network, receiving passive revenue based on transaction volume, in excess of fees paid. ### Schnorr Signature A type of digital signature scheme that allows for the efficient and secure signing of transactions and messages. ### FROST Flexible Round-Optimized Schnorr Threshold (FROST) is a somewhat natural conversion from secret sharing of private keys to secret sharing of signatures, that is, a protocol describing how to use key shards to construct signature shards which can be put together to construct full signatures without revealing the shared sharded key.