National sign languages are unique visual languages used by the deaf communities in specific countries. Each national sign language has its own grammar, vocabulary, and cultural nuances, making it distinct from other sign languages. For example, American Sign Language (ASL) is primarily used in the United States, while British Sign Language (BSL) is used in the United Kingdom. These languages are not universal; they evolve based on the local culture and the needs of their users. National sign languages often reflect the history and identity of the deaf community within a country, fostering communication and connection among its members.