What is a Delegator?

A delegator is another name for someone that stakes their SOL, thereby helping to secure the network and earning rewards in the process. Simply put, a delegator is any user that delegates (stakes) their SOL to a validator either directly or through a stake pool like RunStake. This gives the validator the ability to validate new blocks on the Solana network thereby strengthening it overall.
Anyone who has some SOL in their wallet may delegate it – and earn rewards by doing so.