A diploma is a specific academic award usually awarded in professional/vocational courses. Diploma programs provide education within your given field and get you into the work force sooner.
The Diploma in Engineering is a programme focused on practical and skills-oriented training. It is a technical degree that only covers the essentials when ranked with an undergraduate degree.
Bachelor/Undergraduate courses serves as an essential prerequisite for entry into most professional careers. So, it is a critical component for anyone looking for any career advancement.
Master courses can be a viable option for those who want to further their knowledge of a particular subject, explore other areas of interest after having completed an undergraduate course.
A postgraduate diploma is a shorter qualification than a masters degree, although at the same academic level. These courses are offered to students who have already completed a bachelor's course.
Doctorate course is the highest level of academic course. While a doctorate is required for very few careers, it is growing in popularity, not only among academics but professionals too.
It's not necessary that everyone has to be a doctor or an IIT engineer. You can also be a technician, mechanic, health worker etc. by doing study of vocational, teaching, veterinary and training courses.