Layer 2 is the name of the protocol that offers scalability by deploying high throughput for transactions while inheriting all the security features of any blockchain network. One of the biggest setbacks of Ethereum is the limited transactions it can facilitate within a second.
This often leads to higher transactional charges. Layer 2 offers a solution to this exactly bottleneck problem, while taking off a substantial load from Ethereum. With the Layer 2 solution, transactions are facilitated outside of the underlying blockchain,
This significantly increases the number of transactions per second. The zero process and optimistic rollups are two of the most commonly used Layer 2 solutions. But at the same time, Layer 2 still inherits the security offered by the given blockchain such as Ethereum.