Peercoin (PPC) is a cryptocurrency that was launched in 2012 by Sunny King and Scott Nadal. It is based on a hybrid proof-of-work/proof-of-stake consensus mechanism, which means that it uses both mining and staking to secure the network and validate transactions. This makes it more energy-efficient than other cryptocurrencies that rely solely on mining. Peercoin also has a fixed inflation rate of 1% per year, which means that the supply of coins will increase at a predictable rate. This makes it more stable and predictable than other cryptocurrencies that have unpredictable inflation rates.

One of the unique features of Peercoin is its use of checkpoints, which are blocks that have been validated by the network and are considered to be permanent. This helps to prevent attacks on the network and ensures that transactions are secure. Peercoin also has a built-in governance system that allows coin holders to vote on proposals and changes to the network. This helps to ensure that the network is run in a decentralized and democratic way. Overall, Peercoin is a cryptocurrency that offers a unique combination of security, stability, and energy efficiency, making it an attractive option for investors and users alike.