You’ve heard about Starknet, Polygon, and Albitrum blockchains and it could be a tad confusing while trying to understand why they all exist, and the role they play. A key takeaway is that they are all scaling solutions to scale Ethereum.

The Problem

Think of Ethereum as the lead actor in a movie, while Polygon, Optimism, Abitrum, and others as supporting characters; with one common goal - to make a blockbuster movie.

Similar to lead characters in movies, just as they can't play every role, Ethereum cannot meet every requirement that makes a Blockchain. It is almost impossible for Ethereum to be decentralized, secure, and scalable all at once. One has to give, but which?

Decentralization is the very air the Blockchain breathes, and security is non-negotiable, therefore, scalability has to bear the brunt. Now this is where other blockchain networks come in, to scale Ethereum. Which means to help Ethereum process multiple transactions per second, and reach faster finality.

Why does scalability matter?

“Scalability refers to the ability of an organization (or a system, such as a computer network) to perform well under an increased or expanding workload. A system that scales well will be able to maintain or increase its level of performance even as it is tested by larger and larger operational demands.” -Investopedia

Ethereum can currently process about 15 transactions per second(TPS). For a technology with different use cases and clamoring for adoption, its low TPS causes network congestion and increases the cost of gas fees on Ethereum.

Also, beyond the transfer of assets, many decentralized applications (Dapps) that solve world issues are built on Ethereum. Scaling will enable Ethereum to “accommodate” and run as many software solutions as possible.

The Solution

Scaling solutions are separate Blockchains that help scale Ethereum. They may or may not use Ethereum as their base layer, but they address the scalability challenges of Ethereum and reduce the workload and network congestion on Ethereum.

There are so many scaling solutions, rollups, state channels, sidechains, Validium, Plasma, etc. However, only scaling solutions that rely on Ethereum for security and data availability are referred to as Layer 2.

The reason is that they process transactions off-chain and submit the transaction proof back to Ethereum thereby inheriting Etherum’s security. e.g rollups like Polygon zkEVM, Optimism, Arbitrium, Starknet e.t.c

Because layer 2s process transactions off-chain, they can process as many transactions as possible, roll them into batches, and then submit them on Ethereum. Thus, increasing Etherum’s transactions per second(throughput), and reducing gas fees by distributing the cost across the transactions in a batch.

These solutions have facilitated the development of more technology innovations and Blockchain use cases.