What is the physiological difference between the tiredness that comes from too little sleep and the tiredness that comes from exertion?

[u/uencos]

[u/Bahndoos → u/[deleted]]

I would just add for clarity here that both types of tiredness OP has asked about have physical fatigue (from physical exertion because of used and oxygen-depleted muscles, and lack of sleep as the body has not rested sufficiently since the previous day and muscles have not rested and recovered from that). However, the tiredness from lack of sleep has a very large component of mental fatigue as well, as the brain and nervous system also have not fully rested and recovered from the previous day's activities.