Generally speaking, environment refers to the conditions in which an individual and/or computer operates. These may be simply whatever conditions happen to prevail in a particular location, or may involve special conditions necessary for the proper operation of the equipment. For example, some systems need to be in an air-conditioned environment.
In computing, the term environment refers to the particular hardware and software configuration available to a computer user. Most commonly, the term environment refers to a particular operating system, such as a Windows environment.
In computing by means of DOS, the term environment refers to an area of computer memory in which system information is stored, such as command prompt data. In DOS, "environmental" settings are created by means of the SET command.