Participants of the Proof of Work method receive a reward in the respective crypto currency for solving complicated cryptographic tasks. The solution of the task is marked in the block chain by the generation of a new block. This process is called mining. The solution of the arithmetic problem proves that the calculation method and the transactions were carried out without errors. Solving the task requires a lot of time and energy, which makes it very cost-intensive. Miners and graphics card manufacturers are always trying to develop new devices to meet the high demands.
With the Proof of Stake method, the crypto currency is not created by a complicated calculation task. In simple terms, small portions of the crypto currency are instead held in a wallet (account) and unlocked by the process. This process is also known as staking. With the entirety of shares, each participating user validates the transactions that are processed via the block chain, thus maximizing the security of the network. As a reward, each investor receives an amount for the amount of coins held. If one were to compare this reward with the financial world, one could also speak of interest. Depending on the crypto-currency, these range between two and ten percent per year. This sounds a lot in the first moment, especially in comparison to a building society contract or a share investment. However, due to the strong fluctuations of most crypto currencies, an experienced user can easily earn ten to 20 percent profit per month. Crypto currencies based on this method account for only a small part of the market capitalization. The best known coins are Stratis, PivX and Reddcoin.
Summarized:
Proof of Work
more popular method
time and cost intensive
difficult to mine enormous power consumption

Proof of Stake
easier than Proof of Work
unfair allocation of interest
minimum amount for interest distribution