A sign language is a means of communication that conveys meaning through a combination of body language (particularly the shape,position and movement of the hands) .

as well as lip patterns and facial expression It is said that systems of communicating by signs may be even older than speech.

The development of sign languages is common especiall in deaf communities. These languages are used not only by the deaf, but also by their friends and families. There are even examples of whole local communities using asign language when alarge proportion of the population is deaf as in the case of Martha's Vineyard Sign Language in the USA.

Sign languages are not connected to spoken languages and many different ones are used in countries throughout the world. Although it may seem unbelievable, the British and American sign languages have on similarity to each other,even though the same oral language is spoken in these countries.