I'm trying to understand how the mining process works. Specifically, my understanding is the local miner works on blocks and add them to their local blockchain if they succeed. It may turn out that this isn't the longest chain of blocks (because there are other miners working in parallel) and when that longest chain arrives at the miner, the miner will discard its local (shorter) subchain in favor of the new one.
My question is if the local node (who's also a miner) is asked for information from the block chain before that longest chain arrives, how would it know that these blocks may still change in the future and shouldn't necessarily be trusted?
I apologize if the whole question seems confused. It's only a reflection of my own confusion on the topic.