What is blockchain layer-0, 1, 2 and 3
There are many different opinions on blockchain layer-0, 1, 2 and 3, but in general, they are divided into the following categories:
Blockchain layer 0:
Layer 0 is the base of blockchain, It serves as the root layer, allowing cross-chain interoperability with all Layer 1 protocols like ETH, BNB, ADA … This layer includes the Cosmos, Polkadot and UniChain platform.
Blockchain layer 1:
Layer 1 is the implementation layer, It can be derived from layer 0 or use protocol from layer-0 to maintain the decentralized functionality. Blockchain network like ETH, BTC, UNW … are called the layer-1 blockchain
Blockchain layer 2:
Focus on improving the scalability of layer-1 blockchain. Blockchain like AVAX, Polygon ... are the layer-2 blockchain
Blockchain layer 3:
Also referred to as the “application layer”. The main task of this layer is to host the Dapps and many other protocols that enable other apps. Smart contract, Gamefi, Defi application … are the layer 3.
However, personally, I think the concept of layer-0 blockchain is incorrect. Blockchain layer-0 should be the hardware infrastructure such as the computational units, network station, server, mobile devices … or the hardware wallet. The protocol such as p2p communication, turing machine, consensus algorithm … are software based and should be included in any blockchain layer-1 platform. If It does not link or be used in any decentralized infrastructure then It’s just a library, software module, protocol and function nothing.