Delegated Proof of Stake (DPoS) is a type of consensus algorithm considered by many to be a more efficient and democratic version of the PoS algorithm. It’s also an alternative to the energy intensive proof of work (PoW) consensus algorithm.
DPoS was developed and created by Dan Larimer, an American software developer and founder of cryptocurrency projects BitShares, Steem, and EOS. The first implementation of DPoS was on BitShares in 2013 and has since been implemented on Steem, Lisk, Nano, Ark, or Tezos.
Unlike PoS which uses validators that stake tokens and gain voting power to achieve consensus, DPoS achieves consensus by both real-time voting combined with a social system of reputation. This model is said to make DPoS the most decentralized consensus protocol compared to all others because every token holder can exercise a degree of influence over the network.
In other words, stakers in the system outsource their work to a few delegates that secure the network on their behalf. These delegates are voted in by stakeholders and the larger the stake, the more voting power a staker has. Trustworthy delegates who have a good reputation and value proposal get elected and if an elected delegate/node misbehaves or is inefficient, it is quickly replaced by another.
As for advantages of DPoS blockchains, they are more scalable and able to process more transactions per second than PoW and PoS blockchains. Other advantages include savings on energy costs and more decentralization. As for disadvantages, sufficient decentralization can never be achieved if the blockchain hopes to highly scalable. There must be a balance between the number of block producers and the scalability of the network.