To understand why Linux has become so popular, it is helpful to know a little bit about its history. The first version of UNIX was originally developed several decades ago and was used primarily as a research operating system in universities.
Usage Note: Disabled is the clear preference in contemporary American English for referring to people having either physical or mental impairments, with the impairments themselves preferably termed disabilities.
The dictionary defines disability as a physical or mental handicap, especially one that prevents a person from living a full, normal life or from holding a gainful job.. The Social Security Administration however, uses a more complex method to define disability.