What is the main difference between a family doctor and an internal medicine doctor?

Different: A family practitioner is trained to provide primary care for patients of all ages, including pediatrics, adolescents, adults and geriatric patients, internal medicine doctors focus on adults and geriatric patients.

Whole family: This may be subject to opinion. The main difference is that a family doc will be able to see all ages starting from newborn to the very old. Also a good number of family doc also do obstetrics and are able to follow the mother and newborn. Therefore the whole family including extended family can be seen by the same doc. Internal medicine are more extensively trained about hospital medicine.

F.P. =Broader scope: Family practice (f.P.) doctors are really generalists and will see children (pediatrics) , do office surgery (biopsies, etc..) and some f.P. 's still deliver babies (i did for 15 years). Internists specialize in the care of adults and deal with chronic problems diabetes, high bp, etc.