What is the difference between physical and occupational therapy?

Briefly, and in general, physical therapy (PT) addresses gross motor issues and occupational therapy (OT) addresses fine motor issues. That means that PTs work with activities that involve arms, legs, and spine. OTs work with activities involving the smaller joints specifically hands. OTs also help people with self-care activities such as dressing, bathing, cooking, toileting, and eating.
While in school OTs work in a mental health environment for one of their placements and PTs do not.

PTs work with mobility - walking, climbing, wheel chair training and fitting; foot, knee, ankle, hip, shoulder, elbow and spine rehabilitation, cardiac recovery, and balance issues. I taught young children - ages 2-5 - who had many disabilities, to walk, sometimes teaching them to use a walker. I also taught them to go up and down stairs, open doors, catch and throw balls, kick balls, climb ladders, swing, ride a bicycle, etc. I also worked in adult rehabilitation in hospitals with people after joint replacements, stroke, heart attack, debilitating illness. I taught them to roll over in bed, get into and out of bed, walk, stand up and sit down, use crutches.

Both OTs and PTs work with people of all ages, with rehabilitation needs after surgery, injury, illness, and spinal cord or brain damage. Both can work in hospitals, schools, rehabilitation centers, private practice, and other environments.

This does not begin to cover the range of activities both OTs and PTs work with, but I hope gives you an idea about how the work is different between the two fields. I will also say that in some work environments PTs and OTs never overlap in the work they do, and in some environments there could be some overlap; they may address the same difficulty from slightly different perspectives.

Good question. For more information go to the American Physical Therapy Association website: apta.org; and the American Occupational Therapy Association website: aota.org