PT stands for Physical Therapy, which is a healthcare profession focused on evaluating, diagnosing, and treating movement disorders and pain caused by injury, illness, or disability. Physical therapists use various techniques, such as exercise, manual therapy, and modalities like ultrasound or electrical stimulation, to improve patients' mobility, function, and quality of life.

PTA stands for Physical Therapist Assistant, which is a healthcare profession that works under the supervision of a licensed physical therapist. PTAs perform many of the same tasks as physical therapists, such as providing therapeutic exercise and manual therapy, but they do not evaluate or diagnose patients.

In summary, physical therapists are licensed healthcare professionals who diagnose and treat movement disorders and pain, while physical therapist assistants work under the supervision of physical therapists to help implement treatment plans.