The most popular consensus algorithms are Proof of Work and Proof of Stake, but there are many more. Some are combinations that take parts from both systems, and others are completely different ways of doing things.
We won’t talk about them here, but if you want to learn more, check out the pieces below:
Delayed Proof of Work Explained
Leased Proof of Stake Consensus Explained
Proof of Authority Explained
Proof of Burn Explained