What's StagedBuilt folder is for?

Hello fellow UE Community,

Just out of curiosity, UE seems to have many redundant built folders so I’m wondering what’s each of them are actually for? Can we safely delete most of them to save backup space?
In any case, we found that files in Saved/StagedBuilt are actually quite complete as far as our dedicated server built go. Can we use these files instead of the normal output binaries? What’s the different here?

My gratitude in advance for anyone who cares to help clear this up. Best.