What does "stored" mean? Does it mean "temporarily buffered?" If so, most networking technologies meet that criteria, and iCloud might too if it merely buffer

What does "stored" mean? Does it mean "temporarily buffered?" If so, most networking technologies meet that criteria, and iCloud might too if it merely buffers in RAM. Does it mean "unreadable in cleartext" by Apple? Possibly, but this test doesn't answer that question.