Blockchain networks are secure and decentralized by design, but with their increasing popularity, scalability becomes a very important issue. Each transaction added to a primary blockchain needs to be verified by all participants of the network, which can make processing slow and expensive. That is where cryptocurrency layer 2 comes in. Layer 2 functions as a secondary network on top of the core blockchain, where the majority of transactions are able to be processed off-chain yet still maintain the security and integrity of the base network. Learning how Layer 2 functions involves exploring its principles of operation step-by-step.