“Explain why getting 8 hours of sleep leads to a higher quality of sleep than 4

“Explain why getting 8 hours of sleep leads to a higher quality of sleep than 4 hours of sleep (besides 8 hours being twice as long as 4 hours). In your answer, be sure to summarize the sleep cycle.
(To earn full points, your answer should include a summary of the sleep cycle and the differences in the first few hours of sleep compared to the last few hours of sleep).”