This document covers an introduction to sign language including the types of sign language, who uses sign language, why sign language is important, and provides a reference. It discusses that sign language involves hand shapes, movements, and facial expressions to communicate instead of speaking. There are two main types - alternate sign language used in limited contexts and primary sign language which is the first language of deaf communities. Sign language is important for deaf people to exercise their rights and access information as it allows communication without spoken language.