DPoS (Delegated proof-of-stake) is an algorithm for achieving consensus in a decentralized environment. It is an alternative to PoW (e.g. Bitcoin) and PoS (e.g. Peercoin) consensus algorithms. DPoS was developed in 2014 as part of the Graphene project.
DPoS Basic Operating Principle is to separate voting and validating participants. Network members, who have voting rights (delegators), are not the ones creating blocks (validators). Delegators trust validators by delegating their coins to them, essentially voting with their stake in favour of a validator.
Validators themselves have zero voting power. Their voting strength is directly dependent on the stake of delegators, who have trusted them with their coins.