⛓️🦓 Groth16 is the zk scheme that was the first to market. Things have evolved in new ways, the basics remain the same. This series by Coinmonks is a great technical peak under the hood of how a ZK system really works.
https://medium.com/coinmonks/under-the-hood-of-zksnark-groth16-protocol-2843b0d1558b