What's the difference is between doctors of 'internal medicine' and 'general practice'?

One is a specialist. General practice usually means that the doctor has completed one year of hospital training after medical school. Internal medicine doctors are specialists in the medical care of adults. They complete 3 or more years of training after medical college and must pass exams to become "board-certified" in internal medicine.
Adult medicine. Internal medicine doctors are experts in caring for adults, but general practice doctors take care of people at any age, including babies.