Subsequent sections will go into the concept and application of measurement more fully. The components of the WHO model are hierarchic in that they represent increasingly complex activities. The classification system, however, is not strictly linear. The presence of an impairment does not necessarily lead to a handicap. The new term denotes that the limitations and barriers people face exist in the community or society at large, and are not a limitation of the person.
Disability is a condition, and disablement is the state of a person with that condition.