What is the difference between call and transaction in ethereum?

Question

Cryptocurrency

Good evening, I roughly understand the difference that the call is processed locally on the PC. But I don't quite understand, ie. does it supposedly emulate a transaction by performing the functions of a contract?
If so, what will happen if other nodes have worked out the contactor function on the blockchain?
And I'm also interested in the question, how long is the result of the contract stored? Those. got a hello world result, does it stay in the transaction forever? How long can I receive this data?