Cupping therapy is an ancient form of Ayurveda, but the therapy is more so used in Traditional Chinese Medicine (TCM) to remove stagnation in the body and stimulate the flow of energy (Qi). Cupping with fire involves warming and placing glass cups on the skin. By warming the air within the cup, a vacuum is created, and when applied to the skin, the tissue is drawn up into the cup. More than human fingers can do, cuppings loosens fascia / connective tissue, somewhat similar how deep tissue massage can break up scar tissue. Like acupuncture and massage, cupping increases blood flow (significantly). 

Cupping may cause temporary bruising and soreness, but this is often a sign that the treatment has been successful in removing toxins and stagnation!