The iliac bones are large, flat bones that form the upper part of the pelvis. Each person has two iliac bones, one on each side of the body. They are shaped like a wing and provide support for the trunk, as well as attachment points for various muscles and ligaments. The iliac bones consist of three parts: the ilium, ischium, and pubis. The ilium is the broad, upper portion, while the ischium forms the lower part, and the pubis is located at the front. Together, these bones help protect internal organs and facilitate movement in the lower body.