The abbreviations you listed—MD, MS, MDS, MPH, and M.Phil.—are all postgraduate degrees, primarily in medical and health sciences, but they differ in focus and scope:

MD (Doctor of Medicine)

• Field: Medicine
• Duration: 3 years (in most countries)
• Focus: Clinical and non-surgical specializations (e.g., Internal Medicine, Pediatrics).
• Eligibility: MBBS (or equivalent undergraduate medical degree)

MS (Master of Surgery)

• Field: Surgery
• Duration: 3 years
• Focus: Surgical disciplines (e.g., General Surgery, Orthopedics).
• Eligibility: MBBS

MDS (Master of Dental Surgery)

• Field: Dentistry
• Duration: 3 years
• Focus: Specialized branches of dentistry (e.g., Orthodontics, Oral Surgery).
• Eligibility: BDS (Bachelor of Dental Surgery)

MPH (Master of Public Health)

• Field: Public Health
• Duration: 1–2 years
• Focus: Epidemiology, health policy, environmental health, etc.
• Eligibility: Open to graduates from various backgrounds—MBBS, BDS, nursing, social sciences, etc.

M.Phil. (Master of Philosophy)

• Field: Research-oriented; can be in various disciplines (sciences, humanities, etc.)
• Duration: 1–2 years
• Focus: Research methodology and dissertation work; often a precursor to PhD
• Eligibility: Master’s degree in a relevant field