Execution & Finality
What a transaction contains, when it is valid, and when it becomes irreversible.
A transaction
T = { from, to, value, data, nonce, signature }Who sends it, where it goes, how much value moves, what it calls, its sequence number, and the proof the sender authorised it.
Validity
Valid( T, S(t) ) = 1 ⇒ S(t+1) = F( S(t), T )
A transaction only executes if it is valid against the current state: correct signature, correct nonce, sufficient balance, and enough gas.
Proves who initiated the transaction. Without it, anyone could spend your balance.
A per-account counter that prevents the same transaction being replayed twice.
Determines the state after the transaction: balances, positions, market state.
Guarantees the data is published so the result can be re-verified by anyone.
Defines the moment after which the transaction can no longer be reverted.
Confirmation vs finality
Seeing a result in an interface is not the same as finality. A transaction is only economically safe once its data is published and the settlement layer treats it as irreversible.