Quiz content: What is Ethereum

[konopkja]

This is a sub-task of: #7461

Prepare content for quiz on page:
https://ethereum.org/en/what-is-ethereum/

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 is the big difference between Bitcoin and Ethereum?

A. Bitcoin has middlemen that mediate transactions, Ethereum does not.
B. Ethereum is programmable, Bitcoin is not.
C. Ethereum has middlemen that mediate transactions, Bitcoin does not.
D. Ethereum preserves privacy, Bitcoin does not.

Explanations:

A. & C. The whole point of cryptocurrency, any cryptocurrency, is that you can transact directly with whoever you wish, without the need for middlemen.
D. Every node needs to be able to verify the blockchain's history from the beginning until the present. Therefore, there are no secrets on the blockchain. The only way to preserve privacy on the blockchain is to use private keys (and therefore identities) that cannot be traced back to you. This is possible on both Bitcoin and Ethereum.

[qbzzt]

What are smart contracts?

A. Contracts that include provisions for judicial review
B. Programs running on the Ethereum network that can receive input only from external transactions
C. Programs running on the Ethereum network that can receive input only from other programs running on the Ethereum networks.
D. Programs running on the Ethereum network that can receive input either from external transactions or other smart contracts.

Explanations:

A. Ethereum is a computer protocol. It is not concerned with judicial review.
B. No, smart contracts can also receive input from other smart contracts, which is what gives us composability (the ability of one smart contract to use another, for example for a market such as Uniswap to use ERC-20 tokens)
C. No, smart contracts are the only kind of program running on the Ethereum network itself. They have to be activated by a user transaction, either directly or through another smart contract.

[qbzzt]

Which of the following cryptocurrency activities can you do with Ethereum, but not Bitcoin?

A. Send money to your neighbor.
B. Send money across state lines.
C. Send money across international borders.
D. Take out a loan using ownership of a digital asset as collateral, without waiting for a off-chain underwriter to approve (either a human or software running on a server somewhere rather than on the blockchain itself).

Explanation (for all of them):

Bitcoin is a payment network. You can use it for payments. However, because it is not programmable it is difficult to add new assets on top of it, let alone build automated services for loans, etc.

[qbzzt]

What actions can you do with transactions on a blockchain?

A. Create new transactions, read existing ones, update existing transactions, and delete existing transactions.
B. Create new transactions, read existing ones, and update existing transactions, only.
C. Create new transactions and read existing ones, only.
D. Only read existing transactions.

Explanation (for all of them):

A blockchain is an unalterable record. As such, you can submit new transactions and read existing transactions, but that's it. Even if one or more servers on the network attempt to rewrite history, the attempt is easy to catch.

[qbzzt]

What is Ethereum's uptime (since it got started in 2015)?

A. 99%
B. 99.9%
C. 99.99%
D. 100%

Explanation (for all of them):

Ethereum runs on thousands of servers (called nodes, see https://etherscan.io/nodetracker). Individual nodes go down, but as long as some nodes are up the network, overall, is up and can process transactions.

[qbzzt]

You put information up on the blockchain. Who can decide to remove it?

A. Nobody has that power
B. You as the owner
C. The Ethereum Foundation
D. The legal system

Explanation (for all of them):

The blockchain is an unalterable record. You cannot remove information you put on the blockchain, and neither can any third party, whether it is an advisory to node operators (The Ethereum Foundation), or has the coercive power of a nation state at its disposal (the legal system).

[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.