Explore Sign Languages in more detail :
Sign languages are distinct and separate from spoken languages. In contrast to spoken languages that are characterized as auditory-oral, relying primarily on speaking and listening to convey information, signed languages are described as visual-gestural. They depend on facial expression, hand configurations, manual and body movements to make meaning. They are languages of the eye, not of the ear. Sign languages were not invented, but developed naturally as the means of communication within Deaf communities.
Although sign languages rely on the visual mode, it is incorrect to think of them as a set of gestures or as a picture language. Sign languages are complete, legitimate languages in their own right with their own vocabularies, grammar, syntax and morphology. It is also inaccurate to view sign language as an adjunct or support to spoken language. While sign systems for representing spoken language on the hands have been developed for use as educational tools (e.g., Signed English), these are not the same thing as the natural sign language of the Deaf community. For more information, please visit this World Federation of the Deaf website page on sign language.
It is often thought that sign language is universal and that Deaf people around the world all use the same sign language. But this is not the case. Just as with spoken languages, sign languages differ across countries and communities. Estimates are that there are 130 distinct world sign languages, although this number may not take into account all dialects and undocumented sign languages. A form of International Sign Language (ISL) can be used when deaf individuals from different countries meet, but this form of signing does not allow for the same depth of communication as a full-fledged sign language. Please visit this HandSpeak website page to find more information on International Sign Language (ISL).
Sign language is used in every region of the world, and please visit this Gallaudet University Library website page for links to examples of sign languages used in countries around the globe. It is important to recognize that even where there is a shared spoken language across countries, there may not be a common sign language used by their Deaf communities. For example, American Sign Language (ASL) used in the USA is very different from British Sign Language used in the UK, even though these are both English-speaking countries. Please visit this Deafness Cognition and Language Centre (DCAL) website page from University College London (UCL) to find more information about the ways in which sign languages are distinct from each other.