When you see an Occupational Therapist and have Occupational Therapy the focus of the Occupational Therapist is to help the person improve their ability to perform normal activities of daily living.
A Physical Therapist is a Therapist sorta like an Occupational Therapist but instead the main focus of the Physical Therapist is to improve the ability of the person to be able to move their legs, arms etc in the correct way they were meant to be.
So if you have trouble walking or moving around then the Physical Therapist would be the type of therapist you'd want to see but sometimes you might go to both a physical therapist and occupational therapist depending on your needs.