The document summarizes various cultural, religious, medical, and social aspects related to the human belly button or navel. It discusses different terms used to describe the navel across cultures. It also explores the navel's significance in Greek mythology, Hinduism, Christianity and other religions. Medically, it examines the navel's embryological development and use as a diagnostic indicator. Socially, it mentions portrayals of the navel in media and body modifications like piercings.