Sign Language is a language that prioritizes manual communication, body language, and lip motion, not sound, to communicate. Deaf people are the main group that uses this language, usually by combining hand shape, orientation and movement of the hands, arms, and body, and facial expressions to express their thoughts.

Contrary to the opinion of many people, in reality there has been no successful international sign language applied. Sign language is unique in its type in each country. Sign language can be different in countries that speak the same language. For example, even though the United States and Britain have the same written language, they have completely different sign languages ​​(American Sign Language and British Sign Language). The opposite also applies. There are countries that have different written languages ​​(for example: English with Spanish), but use the same sign language.

For Indonesia, there is a sign language, Indonesian Sign Language (BISINDO) whose development is supported by one of the donor agencies from Japan involving the Chinese University of Hong Kong and the University of Indonesia. For the Indonesian Language Sign System (SIBI) is a sign system (not sign language) made by people to hear without involving deaf people in special education education.

The following are the American (ASL), English (BSL) sign language, and of course Indonesia (SIBI and BISINDO).