A medical intern is a person who just finished school to become a doctor and is now training in a hospital to become a fully licensed doctor. It's like they are going to "doctor school" but in a real hospital instead of a classroom!
During their training, interns work with other doctors and nurses to take care of patients who are sick or hurt. They do things like check a person's blood pressure, listen to their heartbeat, and ask them questions about how they are feeling.
Interns also learn how to read medical charts and interpret test results. They watch surgeries and procedures to learn how to do them themselves one day. They also spend a lot of time studying and reading about medical conditions and treatments.
Overall, becoming a medical intern is an important step in a doctor's journey towards helping people feel better and live healthier lives!