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Rollup

Scaling solution that executes transactions off-chain and posts proofs on-chain

What is Rollup?

A Layer 2 scaling technique that bundles (rolls up) hundreds of transactions off-chain, then posts a single cryptographic proof back to the main chain. Rollups inherit the security of the base layer while dramatically increasing throughput and reducing fees. The two main flavors — optimistic and zero-knowledge — differ in how they prove correctness. Rollups are the consensus answer to 'blockchains are too slow and expensive.'

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In plain words

"An express lane next to the highway — transactions process off the main road, then a summary receipt gets posted back. Faster, cheaper, just as secure."

How it works

Key takeaways

  • Batches transactions off-chain for speed

  • Posts proof back to Layer 1 for security

  • Reduces fees while inheriting L1 trust

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Real-world example

Arbitrum processes thousands of transactions off-chain, then posts a single proof to Ethereum. Users get Ethereum security at 10x lower fees.

Related terms

Interoperability

Blockchains talking to each other

Smart Contracts

Self-executing code that automates agreements

DeFi

Decentralized Finance

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