What is Optimism and the OP Mainnet?

In the realm of blockchain technology, scalability remains a significant challenge. This is where OP -2.87% Mainnet, a Layer 2 scaling solution for Ethereum, comes into play. It's specifically designed to provide faster transactions at a fraction of the cost, helping to address Ethereum's scalability issues.

In this article we'll take a look at OP Mainnet and the wider Optimism ecosystem.

What is the OP Mainnet?

The OP Mainnet, formerly called Optimism, is the main blockchain network in the Optimism ecosystem. It was built by OP Labs and runs on its software called the OP Stack.

OP Mainnet is a Layer 2 network that operates on top of Ethereum's architecture, acting as a minimal extension of the main Ethereum layer. It allows developers and crypto users to enjoy quick transactions at low fees while maintaining the security of Ethereum's architecture.

Optimism also has a "Superchain" thesis. This is the idea of connecting multiple Layer 2 networks through shared code and the ability to interact with each other. Coinbase's Layer 2 network Base was also built using the OP Stack and is part of this Superchain idea.

The Worldcoin app is also now based on the OP Mainnet, having moved there from Polygon.

The OP token runs at the core of the OP Mainnet and is used for paying transaction fees. The token was given out in an airdrop in May 2022 to wallets that had interacted on the OP Mainnet or donated to Gitcoin on the Ethereum blockchain. The network has now done three airdrops in total.

How does Optimism work?

Optimism-based networks operate using a method called "optimistic rollups." This technology processes transactions off-chain in batches, significantly reducing transaction fees and alleviating network congestion.

Optimism's rollup technology bundles multiple transactions from Ethereum’s Layer 1 into a single transaction, effectively distributing the transaction fee among all users involved in the transactions. The rollup is executed on Optimism’s Layer 2 network OP Mainnet, while the transaction data is posted to Ethereum’s Layer 1 for processing.

This process is "optimistic" in that every transaction is initially assumed to be valid on Optimism’s Layer 2, and no computations are performed. If a transaction is suspected of being fraudulent, the system runs fraud-proofing to verify the transaction.

Optimistic rollups are different from zero-knowledge rollups, which provide a proof that all transactions are valid before pushing them onto the main Ethereum blockchain. These are sometimes known as pessimistic rollups. Since such proofs are expensive, optimistic rollups typically provide cheaper transactions.