American Sign Language (ASL) is a visual-spatial language that uses hand gestures and shapes to communicate within the deaf community. There are five key parameters in ASL: hand shape, palm orientation, location, movement, and non-manual signals/facial expressions. The document provides examples of common greetings and sentences in ASL, demonstrating hand shapes for letters and signs for concepts like "name", as well as how to sign phrases like "I love you" and "goodbye".