disability, handicap, impairment

Word	Explanation	Example
disability	used to refer to an on-the-job injury One is "On disability" when they are being paid by their employer while recovering from the injury.	When you are disabled it can be even more difficult to find a job, especially if you have limitation because of your disability. disability benefit = Erwerbsunfähigkeitsrente
handicap	a specific ailment, injury, or infirmity that a person suffers from which limits their abiltity to function in a normal capacity This is the official term used when the Department of Motor Vehicles issues a special permit to allow the driver to park their car in a designated area, for example.	Handicap parking spaces are restricted to authorized verhicles 24 hours daily.
impairment	the broadest term - it can mean that there is a disability or handicap, OR it can mean that the person has had too much too drink	The man was driving a car while impaired by alcohol.
All three terms are pretty much interchangeable in many instances but most of the time each is used in a certain way.