What is the difference between a Messenger (Rasul) and a Prophet (Nabi), and why was the Messenger described as the Seal of the Prophets (Khatam An-Nabiyyin) and not the Last Messenger (Ar-Rasul Al-Akhir) in Surah Al-Ahzab, Ayah 40?

The well-known distinction between a Prophet (Nabi) and a Messenger (Rasool) is that a Messenger is commanded to convey the message, whereas a Prophet is not. However, this distinction is not without issues, as a Prophet is also commanded to invite and convey. Sheikh al-Islam Ibn Taymiyyah holds that a Messenger is sent to disbelieving deniers, whereas a Prophet is sent to a believing people who follow the law of a Messenger before him, to teach them and rule among them, citing the verse: (Indeed, We sent down the Torah, in which was guidance and light. By it ruled the prophets who submitted to Allah). As for the reason for mentioning "Seal of the Prophets" and not "Seal of the Messengers," it is because the sealing of prophethood necessitates the sealing of messengership, whereas the sealing of messengership does not necessitate the sealing of prophethood. And Prophet Muhammad, peace be upon him, is the Seal of the Prophets and Messengers.