1, varying degrees
A master is a master and a doctor is a doctor.
2. Different meanings
Graduate students refer to those who are studying for a master's degree, master refers to a graduated master, and doctor refers to a graduated doctor.
3. Different levels of education
Postgraduates are educated, including masters and doctors; Master's degree and doctor's degree, master's degree usually lasts for 2-3 years, and can't exceed 5 years at most; Doctoral students usually last for 3 years.