"Ab" can refer to various concepts, but it is commonly associated with the term "abdominal muscles," often called "abs." These muscles are located in the front of the abdomen and play a crucial role in core stability, posture, and movement. Strong abs can enhance athletic performance and support daily activities. In another context, "Ab" may refer to the abbreviation for "antibody," which is a protein produced by the immune system to identify and neutralize foreign objects like bacteria and viruses. Antibodies are essential for the body's defense mechanisms and are a key focus in medical research and treatments, including vaccines.