Proof of Capacity (PoC) is a consensus mechanism in blockchain technology that uses disk space as the main resource to validate transactions and generate new blocks. Unlike systems that rely on computing power, such as Proof of Work (PoW), PoC allows participants (miners) to utilize the available storage capacity on their devices to store solutions to complex mathematical problems.

In PoC, miners pre-compute and store the results on disk. When new blocks need to be generated, the system will select miners based on the storage capacity they have and the corresponding pre-computation results. This approach is considered more efficient in terms of energy usage, as it minimizes the need for high computing power, and can reduce the environmental impact of mining operations.

PoC offers an attractive alternative in the pursuit of decentralization and security in the blockchain ecosystem, with a focus on using more environmentally friendly resources.