Key Difference: Doctors refer to healthcare professionals who practice medicine. There are many different types of doctors depending upon their focus area. Some of the doctors are involved in patient care while some provide support to the work of these doctors. A doctor may also specialize in one or more sub-specialties.

Doctor refers to a person who is qualified and trained to provide medical treatments to the patients. A doctor possesses the license to practice medicine. There are many different types of doctors depending upon their area of specialization. To become a doctor one needs to attend the medical school. They usually hold a degree in medicine. A candidate must also complete a residency in order to get the license to practice.  There are many different types of doctors depending upon their area of specialization. Some of the common ones include –

General Physician – It refers to a specialist who looks after the non-surgical health of adult patients. They differ from other doctors who practice within the specialized area of medical knowledge. Generally, they look after the hospital patients however; they also see patients in their consulting rooms.

Cardiologist – Cardiologist is a physician who specializes in the area of treatment related to heart, arteries and veins. They primarily look into the cardiovascular system. For patients who require surgeries are often referred to a cardiovascular surgeon who operates the patients for ailments related to heart, lungs and blood vessels.

Dermatologist – The term 'Dermatologists' refer to those doctors who look after the disorders related to skin, nails, hair and related mucous membranes. They also conduct surgical treatments if required. They diagnose and provide treatment for nearly more than 3000 diseases. They look into diseases like acne, skin cancer, nail infections, etc.

Gynecologist – They refer to the doctors who look after the ailments or disorders related to the reproductive system of woman. They generally look into the conditions like infections of uterus, cervix, vagina; they also deal with condition like female cancers. The typical procedures performed by them are hysterectomy, tubal ligation, laparoscopy, cystoscopy, etc.

Dentist – Dentist are doctors who deal with the oral diseases and conditions. They look into a range of dental diseases and conditions with include prevention of tooth decay, oral facial anomalies, malocclusion, etc. If required, dentists perform procedures like biopsies, diagnostic tests for chronic or infectious diseases, screening rests for oral cancer, etc.

Urologist – Urologists diagnose and treat problems and disorders related to urinary system, kidneys and urinary tract infections. An urologist possesses the knowledge of internal medicine, gynecology, pediatrics and other specialists. An urologist can further specialize in areas like Male Infertility, pediatric urology, renal transplantation, etc.

Oncologist- Refers to doctors who diagnose and treat cancer.  There are many different types of oncologists depending upon their specialized areas. For example- a pediatric oncologist deals with treatment of cancers in children and adolescents. Radiation oncologist is specialized in the area of radiation therapy which is required to treat cancer.

Neurologist – Neurology is the branch of study which deals with the nervous system. Therefore neurologist is a doctor who works in the field of neurology. They look into the disorders related to the brain, nerves, spinal cord, etc. They do not specialize in surgery and if required that they refer the patient to the neurosurgeon.

Orthopedist – An orthopedist is a doctor who looks into the injuries and diseases of the musculoskeletal system. They specialize in the skeletal and muscular condition but they can also emphasize on specific parts like foot and shoulders. They provide treatment for congenital or functional abnormalities of the bones by carrying out processes like surgery, casting and bracing.

Psychiatrist – A psychiatrist is a doctor who looks after the mental health. He also deals with emotional problems. They recognize the connection between emotional illness and medical illness. In order to understand the problem of the patients they usual perform medical and psychological test.  There treatments usually include psychotherapy and medications. In sever conditions hospitalization can also be done in order to treat the patients.

Hematologist - Hematology is the field of study which deals with blood. A hematologist treats problems related with red blood cells, white blood cells, platelets, blood vessels, bone marrow, proteins important n bleeding and clotting, etc. Usually hematologists are also specialized to treat people with cancer.

General Pediatrician – This doctor comes under the category of general medical experts. They look into the medical problems of infants, children and adolescents. The word pediatrician has been derived from the Greek words pais means child and iatros which means healer. Abraham Jacobi is known as the father of pediatrics as he is credited for running the first ever children’s clinic in New York.

Gastroenterologist – Refers to a doctor who provides treatment of the diseases of the gastrointestinal tract and liver. The word Gastroenterology deals with the field of study of the esophagus, stomach, colon, small intestine, pancreas, bile ducts, liver and gallbladder. They are trained for carrying out endoscopy.

Hepatologist-These are gastroenterology doctors who are specialized in providing the treatment of liver related diseases like cirrhosis or hepatizes. They may also specialize in the area of liver transplantation.

Nephrologist- Nephrologist is a doctor who specializes in the treatment of  the diseases of kidney. Some of the common problems looked after by the nephrologists are hematuria, acute renal failure, electrolyte disorders, kidney stones, etc. They also provide care to the patients who need renal replacement therapy which includes dialysis and renal transplant patients.

Otolaryngologist – An otolaryngologist is also known as an ENT physician. They are physicians who provide treatments for diseases and disorders of the ear, nose, and throat and associated structures of head and neck. The areas of specialization under otolaryngology are allergy, head and neck, laryngology, otology, etc.

Ophthalmologist – it refers to a doctor who deals with problems of eye and vision care. They provide a range of eye care services like prescription of glasses and contact lanes. They are also trained to perform complex and delicate eye surgeries. An ophthalmologist may also specialize in areas like refractive surgery, ocuplastics, neuro-ophthalmology, etc.

Veterinarian – These doctors deal with the health of animals. They may work as generalists or look after the health of particular type of animal. To become a veterinarian one needs to earn a doctor of veterinary medicine. They look into the diseases of animals which include pets, livestock, etc.

Surgeons- These are physicians who are specialized in the field of surgical procedures.  They operate on specific parts of the body or they address certain types of injuries, diseases or degenerative conditions. There are many specialties within the field of surgery like general surgery, neurosurgery, plastic surgery, otolaryngology, etc.

In addition to this list, there are many doctors who are not involved in patient care but they carry out the activities which assist other physicians like radiologist, pathologist, etc.

Image Courtesy: gisr07.hubpages.com