Does an ethereum node save all transaction history?

Question

I know that a full node keeps the record of a state tree, and in every block there's a list of transactions. My question is, does a full node have to keep all the tx lists? The state tree already saves all the information about the current states of all accounts, so it seems kind of meaningless to remember the whole blockchain history(all the tx), but if this is the case, how can we check our transaction histories?

My guess is that the nodes will keep all the transactions, but they're just for users to look up, not for validating future transactions. Is this correct?

Answer 1

A full archive node will store all the transactions, all transaction receipts, and block headers. Moreover, it will maintain the state trie and storage tries of contracts.

My guess is that the nodes will keep all the transactions, but they're just for users to look up, not for validating future transactions. Is this correct?

You're right. For validation it doesn't have to know the complete transaction history.