Peercoin vs Bitcoin

Do you know the difference between PoS and PoW? It is a very old movie but I think that is very nice!

Proof-of-stake (PoS) is a type of algorithm by which a cryptocurrency blockchain network aims to achieve distributed consensus. In PoS-based cryptocurrencies the creator of the next block is chosen via various combinations of random selection and wealth or age (i.e. the stake). In contrast, the algorithm of proof-of-work (PoW) based cryptocurrencies (such as bitcoin) uses computationally intensive puzzles in order to validate transactions and create new blocks (i.e. mining).
Source: wikipedia.org