Ethereum networks (mainnet, testnet) in Blockchain / Solidity - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the Ethereum mainnet?

The Ethereum mainnet is the primary public blockchain where real transactions happen using real Ether (ETH). It is the live network where users send and receive actual value.

beginner

What is a testnet in Ethereum?

A testnet is a separate Ethereum network used for testing and development. It uses fake Ether and allows developers to try out smart contracts without risking real money.

intermediate

Name two popular Ethereum testnets.

Two popular Ethereum testnets are Goerli and Sepolia. They help developers test their applications safely before deploying on the mainnet.

beginner

Why should developers use testnets before mainnet?

Developers use testnets to avoid losing real money and to find bugs or errors in their smart contracts. Testnets provide a safe space to experiment and fix issues.

intermediate

How does the Ethereum mainnet differ from testnets in terms of transaction cost?

On the mainnet, transactions cost real Ether as gas fees. On testnets, gas fees are paid with test Ether, which has no real value and can be obtained freely from faucets.

What is the main purpose of an Ethereum testnet?

A To send real Ether to other users

B To replace the Ethereum mainnet

C To mine real Ether coins

D To test smart contracts without using real Ether

Testnets allow developers to test smart contracts safely using fake Ether.

Which network uses real Ether for transactions?

A Goerli testnet

B Ethereum mainnet

C Rinkeby testnet

D Sepolia testnet

The Ethereum mainnet is the live network where real Ether is used.

What do you call the fake Ether used on testnets?

A Test Ether

B Real Ether

C Bitcoin

D Gas tokens

Test Ether is used on testnets and has no real monetary value.

Which of these is NOT a reason to use an Ethereum testnet?

A To avoid losing real money

B To find bugs in smart contracts

C To deploy a live application for users

D To experiment safely

Testnets are for testing, not for live user applications.

How can developers get test Ether for testnets?

A From faucets that distribute free test Ether

B By mining on the mainnet

C By buying it on exchanges

D By sending real Ether to testnet addresses

Faucets provide free test Ether to developers for testing.

Explain the difference between Ethereum mainnet and testnets.

Think about real vs fake money and purpose of each network.

Why is it important to test smart contracts on testnets before deploying on mainnet?

Consider risks and safety in software development.