Nabi means Prophet, referring to Allah’s approximately 124,000 chosen human beings.
The term itself appears in the holy Qur’an 43 times. It means
A prophet of and from Allah sent to the people to bring them news and knowledge of the ghaib (the Unseen Truths).
NABI has the knowledge of the Unseen Truths (ghaib):
Allah endows His nabi with the knowledge and wisdom of the Unseen so he can warn the people of the danger for denying the Truth and offer them glad‐tidings for their piety and obedience. To deny a nabi’s knowledge of the Unseen is to deny the title of nabi’ itself because the term nabi means the one who brings the news of the Unseen. For example, when a Muslim recognizes that Muhammad is the Prophet of Allah then he admits that the Prophet has granted knowledge of the ghaib from Allah.
Therefore, denying the knowledge of the ghaib for the Prophet Muhammad is, in fact, denying his status as a nabi, and recognizing his status as a nabi is the fundamental obligation to be a Muslim. Therefore, any Muslim who denies the Prophet’s knowledge of ghaib forsakes his fundamental obligation, rendering him/her faithless. Through the process of wahi (divine revelation) and through dreams, Allah reveals His knowledge to the holy prophets. From Adam to Muhammad, Allah sent about 124,000 Prophets and Messengers, to guide humankind to Sirate‐Mustaqim (The Straight Path). The Prophet Muhammad is Khatimun‐Nabiyyin (the Seal of Prophet hood, the Final Prophet). There will be no nabi or rasul after him because the Guidance from Allah to humankind has been fulfilled with the teachings of the Prophet.