Culture is a word that describes the way people live, how they communicate and how they organise their group of people. Different people have different cultures. People from other countries have different ways of living. The Deaf Community have their own culture, their own language and their own way of organising themselves.
Cultures develop around people's self-identity, i.e., their experiences and ideas about themselves and their place in the world. It is a natural development when people who share similar experiences and identities come together. Cultures gather strength when they are passed down over generations and are enriched with historical knowledge.
Deaf people's interaction with other people and with the world around them is primarily visual. Deaf culture is based on this visual orientation.
Many people seem to believe that by isolating Deaf people from each other, this Deaf cultural identity would not develop. But people seem to have an innate need to congregate with others who are like them in some way and who accept them for who they are, and Deaf people are no different - sooner or later they seek each other out. Ironically, the experience of isolation from the Deaf community and the Deaf culture becomes for many Deaf people one of the commonly shared experiences and hence one of the culture's unifying factors. Source Deaf Australia Inc.
Read more about Deaf Culture at http://www.deafau.org.au/info/dculture.php