The consensus mechanism is also known as the fault-tolerant mechanism used in blockchain systems.
In this all the members of a distributed network come to a mutual agreement about the state of the network.
The two types of consensus mechanisms are proof of work and proof of stake.
Proof of work
This type of consensus mechanism confirms transactions and produces as well as adds new blocks to the blockchain.
Proof of stake
This type of consensus mechanism in blockchain technology, secures networks and validates transactions.