Sign language is a visual language that uses hand gestures, facial expressions, and body movements to convey meaning. It is used by deaf individuals and those with hearing impairments to communicate with each other and with hearing individuals who may also learn sign language. Research in sign language includes studying the grammatical structure, vocabulary, and syntax of different sign languages, as well as investigating how sign languages are acquired and processed in the brain. Additionally, researchers may explore the cultural and social aspects of sign language use, as well as how sign language can be used in education and interpretation services.