Proof of Capacity is a consensus algorithm in which miners use free space on storage drives instead of energy-intensive computations, which makes mining coins cheaper and more environmentally friendly.

Proof of Importance is a consensus algorithm that takes into account not only the size of the balance but also a participant's activity in the network when distributing the right to create blocks.

Proof of Service is a mechanism in which nodes perform useful functions for the network and receive a reward for this, provided they hold a fixed collateral of coins.

Delegated Proof of Stake is a consensus algorithm in which coin holders vote to choose a limited number of trusted nodes that create blocks on behalf of the entire network.

Coin age is a metric calculated as the amount of cryptocurrency multiplied by the time it has been held. The concept is used in proof-of-stake mechanisms.