Gas Fee

• Fee schedule in Ethereum Yellow Paper
• Some opcodes are more expensive than others
  • e.g. multiplication costs 5 gas; shift left costs 3 gas

Storage

• A contract storage is persistent between function calls and transactions
• It is a key-value mapping of 2²⁵⁶ keys. Each value is 32 bytes

Memory

• Memory is volatile
• It is mainly used to store data during execution
• Each message call starts with a cleared memory

Stack

• All computations are performed on the stack
• It has a maximum of 1024 elements
• Access to stack is limited to the top elements
• Access to elements by pop/push to stack

Smart contract Storage

• This is where state variables are stored
• It is persistent between function calls and transactions
• It is a key-value mapping of 2²⁵⁶ keys; each value is 32 bytes long