A family physician and an internist are both primary care physicians.
But an internist is basically like an adult pediatrician but internists usually just care for adults and not children or teens.
But a family physician cares for both adults and children as well as teens.
Family physicians see all kinds of patients while an internist only sees adults and specializes in adults.
So they're both qualified doctors but the main difference is that they treat and see different types of patients.