Ether represented as 1 ether, or 1 ETH, or Ξ1, or ♦1
Smallest unit “wei”.
Faucets are applications on test network that give free ether
Ethereum was made to run smart contracts
The cryptocurrency aspect is an secondary feature on Ethereum
The EVM is a global singleton i.e. runs as a single instance everywhere
Account Types
The type of account created by a wallet is called Externally Owned Account (EOA)
EOA accounts have a private key associated with it
Contract accounts are accounts that have Smart Contract code stored in them
Contract accounts don’t have a private key they are owned and controlled by the smart contract code
Contracts have addresses, can send and receive ether like a EOA account
When a transaction destination is a contract addresses it executes the contract
The transactions data becomes the input for the contract
Transactions can call specific functions in a contract (can pass parameters as well)
Since contracts do not have a private key they cannot start a transaction
Ethereum Clients
Remote clients do not store a local copy of the blockchain
They operate like wallets allowing the creation and broadcast of transactions
They are completely reliant on full nodes to provide them with information
Light clients are similar to SPV clients in Bitcoin
They verify the block headers and using Merkle proof to verify that the transaction is present in a block
Fast sync skips full transaction validation until it synced to the tip of the blockchain