Quiz content: Layer 2 page

[konopkja]

This is a sub-task of: #7461

Prepare content for quiz on page:
https://ethereum.org/en/layer-2/

Each question should be related to the most important aspects of the page. There can be a unique explanation for each correct/incorrect answer.

[qbzzt]

What service(s) does Ethereum (Layer 1) give to Layer 2 solutions?

A. Reliable execution
B. Internal storage
C. Data integrity
D. Data integration and internal storage.

Explanation:

Data availability requires the same data to be replicated across a large number of nodes, which only layer 1 Ethereum can provide. Reliable execution, on the other hand, can be done on layer 2 as long as there is a mechanism to enforce correct results. Internal storage is the result of executing writes to storage, so it happens where the execution happens.

[qbzzt]

What is the major feature provided by Layer 2 solutions that Ethereum, by itself, cannot provide?

A. Security
B. Decentralization
C. Scalability
D. Uptime (reliability)

Explanation:

Ethereum optimizes for security and decentralization at the base layer, and decentralization gives us uptime automatically. A decentralized system with thousands of nodes will have a large number of nodes running at any point in time. Layer 2 solutions typically provide scalability by relying on Ethereum for security, and being less decentralized (but relying on mechanisms running on Ethereum to ensure the execution and internal storage are correct).

[qbzzt]

Which type of layer 2 solution relies on economic incentives to ensure transactions are executed correctly?

A. Zero-knowledge rollups
B. Optimistic rollups
C. Sidechains
D. Validiums

Explanation:

Optimistic rollups have sequencers that post the transactions' data and their results (in state root form) on Ethereum, and verifiers that challenge them. Sequencers that post incorrect results, and verifiers that dispute correct results, pay a penalty. Sequencers that post correct results, and verifiers that dispute incorrect results, get rewarded. This is using economic incentives to encourage honesty.

[qbzzt]

Which type of layer 2 solution relies on mathematics to ensure transactions are executed correctly?

A. Zero-knowledge rollups
B. Optimistic rollups
C. Sidechains
D. Validiums

Explanation:

Zero-knowledge rollups post zero-knowledge proofs that they processed their transactions correctly. Producing those proofs requires a lot of computation, and is not feasible to do on chain. However, to verify the proof only requires a relatively simple computation that can be done on-chain easily.

[github-actions]

This issue is stale because it has been open 45 days with no activity.

[minimalsm]

Closing this out as part of #8094. I've migrated question suggestions here to this Notion doc and will be updating decisions here.