Concepts | Concept Map

• Wallet
• Account
• Transaction Structure
• Nonce
• Gas
• Data Flow
• Mempool
• Digital Signatures

Wallet

A software application that helps you manage your Ethereum account

• Gateway into Ethereum system
• Holds keys
• Create and broadcast transactions on our behalf

Multisig Wallet

Account

‘One private key equals one “account”’

“Not your keys; not your funds”

1. Externally owned account (EOA)
   1. Accounts that have a private key (control over access to funds or contracts)
   2. Can initiate transactions
2. Contract account
   1. Has smart contract code, which a simple EOA can’t have
   2. Does not have a private key; it is owned and controlled by the logic of its smart contract code
      1. Recorded on Ethereum blockchain
      2. Executed by the VM
         1. When a transaction destination is a contract address, it causes the contract to run in the EVM, using the transaction, and the transaction’s data as input
            1. Transactions contain data indicating which specific function in contract to run and what parameters to pass to that function
   3. Cannot initiate transactions
   4. React to transactions by calling other contracts
      1. Composable contracts, money legos
      2. Ex: EOA → Request TX to multisig wallet → Send ETH to another address

• Ethereum contracts are programs that control money that run inside the EVM
  • Created by a special transaction that submits their bytecode to be recorded on the blockchain
  • Once created, they have an Ethereum address
  • Anytime someone sends a transactions to a contract address, the contract runs in the EVM with the transaction as its input
  • Transactions sent to contract addresses may have ether or data or both
    • Contain ether: it is deposited to the contract balance
    • Contain data: the data can specify a named function in the contract and call it, passing arguments to the function

Transactions

• Action initiated by an externally-owned account