POW (Proof of Work) is explained in the original Bitcoin whitepaper: http://bitcoin.org/bitcoin.pdf
DPOS (Delegated Proof of Stake) is explained here: DPOS Consensus Algorithm - The Missing White Paper

Yes, it's a lot of reading. Yes, it's worth it. The future will be decided by those who spend the time to understand things from first principles, not those who ask for things to be explained to them.