World state in Ethereum - Always 1 turn lagging?

Question

About the data in Ethereum block header, there is the State root from the World state trie. However this World state trie contain the whole Accounts states (EOA + CA). In a block, we have transactions which affects the Accounts states.

So with this informations, one question persist : The State root we find in each block header, is from the World state before transactions, or after ? So a new World State is it updated in real time, and the State root in block header is the result of the whole transactions ? Or the State root have always 1 turn lagging?

Thanks in advance for the support.

Regards

Answer 1

The state root saved in a block is the result after processing all the transaction in the block.

From Yellow Paper section 4.3 "The Block"

stateRoot: The Keccak 256-bit hash of the root node of the state trie, after all transactions are executed and finalisations applied; formally H_r.