What is Layer 2? đđ»
A layer 2 is any off-chain network, system, or technology built on top of a #blockchain to help extend its capabilities.
One core requirement for a network, system, or technology to be considered a layer 2 is that it inherits the security of the blockchain it is built on top of.
For example, sidechains are often not considered layer 2s because they usually deploy their own consensus mechanisms and validators, leading to a different set of security guarantees than that of the base layer chain.
The Need for Layer 2s đ
Layer 2s are an emerging technology built on the premise that this scalability limitation exists because blockchains are tasked with too many things.
This is because blockchains today fulfill three core functions: execution, data availability, and consensus.
Layer 2 Security đ
The concept of âproofâ is fundamental to layer 2s in order for them to inherit the security guarantees of a base chain.
Every layer 2 relies on some form of cryptographic proof to settle disputes on the base chain. The most prominent proofs today are fault proofs and validity proofs (also known as zero-knowledge proofs), foundations for the modern-day optimistic rollups and zk-rollups.
