Concept of disability is vital. Unfortunately, there are no universally accepted ways to define disability and to measure it. However, consensus on a definition would enhance evaluation and research. Disability is a dynamic phenomenon. Concept and understanding of human disability are observed to be undergoing continuous modification and consequently administrative attention across the world. Unquestionably, defining disability is a challenging task. However, the international agencies WHO, ILO, UNESCO and UN, have played a valuable role in facilitating the development of definition of disability. Disability is complex, dynamic, multidimensional, and contested. In India, disability condition has been introduced essentially following the medical model. In common parlance, different terms such as disabled, handicapped, crippled, physically challenged, are used inter-changeably, indicating noticeably the emphasis on pathologic conditions. Even so, disability is not defined as a standalone medical condition, but rather as the product of the interaction between the environment broadly defined and the health condition of particular persons.