Proof of Replication (PoRep)
Proof of replication (PoRep) is a consensus mechanism that builds on the proof of work (PoW) model. It is a process through which storage miners prove to the blockchain protocol that they’ve created a unique copy of a specific piece of data on behalf of the network.
Simply put, PoRep is a mechanism that allows the "prover" to show that they're really using network space to store the replicas of a certain piece of data.
PoRep works by having each node in the system commit to a replica of the blockchain state, and then allowing any other node to verify that replica. If a node is found to be "lying" about its replica, it can be "punished" by the network.
In PoRep systems, participants in the blockchain network want to join in as provers in an effort to store as much information as possible. That's because the network rewards participants for their storage space.