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.
What is the Social Security definition of disability? The definition of disability states that an individual must have a severe impairment that has either lasted, or can be expected to last, for a minimum of one year.