CPT stands for Chest Physical Therapy, which is a type of treatment that aims to improve lung function and clear mucus from the airways. It involves various techniques such as percussion, vibration, and postural drainage, which help to loosen and remove secretions from the lungs. Chest Physical Therapy is commonly used in conditions like cystic fibrosis, chronic obstructive pulmonary disease (COPD), and pneumonia to improve breathing and prevent complications.