Accounts (EOA vs contract accounts) in Blockchain / Solidity - Quick Revision & Key Differences

Recall & Review

beginner

What is an Externally Owned Account (EOA) in blockchain?

An Externally Owned Account (EOA) is a blockchain account controlled by a private key. It can send transactions, hold cryptocurrency, and initiate actions on the blockchain.

beginner

What is a Contract Account in blockchain?

A Contract Account is a blockchain account controlled by code (smart contract). It cannot initiate transactions but can execute code when triggered by EOAs or other contracts.

intermediate

How does an EOA differ from a Contract Account?

EOAs are controlled by private keys and can initiate transactions. Contract Accounts are controlled by code and only execute when called by EOAs or other contracts.

beginner

Can Contract Accounts hold cryptocurrency?

Yes, Contract Accounts can hold cryptocurrency and manage it according to their programmed rules in the smart contract code.

beginner

Who controls the actions of an EOA?

The owner of the private key controls the actions of an EOA, including sending transactions and interacting with contracts.

Which account type can initiate transactions on the blockchain?

A Contract Account

B Externally Owned Account (EOA)

C Both EOA and Contract Account

D Neither

Only EOAs can initiate transactions because they are controlled by private keys.

What controls a Contract Account?

A Smart contract code

B Blockchain miner

C User password

D Private key

Contract Accounts are controlled by the code of the smart contract deployed on the blockchain.

Can a Contract Account send transactions by itself?

A Only when triggered by an EOA or another contract

B Yes, anytime

C No, never

D Only if it has a private key

Contract Accounts execute code only when triggered by EOAs or other contracts; they cannot initiate transactions independently.

Which account type holds the private key?

A Contract Account

B Neither

C Both

D Externally Owned Account (EOA)

Only EOAs have private keys that control them.

What happens when an EOA sends a transaction to a Contract Account?

A The contract code executes

B The contract account sends a transaction back

C Nothing happens

D The EOA loses its private key

Sending a transaction to a Contract Account triggers its code to execute.

Explain the main differences between an Externally Owned Account (EOA) and a Contract Account.

Think about who controls each account and how they interact with the blockchain.

Describe how a Contract Account operates when it receives a transaction from an EOA.

Focus on what happens inside the contract after receiving a transaction.