Isolation describes the state of separation or alone-ness of any object, material, energy, space or organism as related to surrounding materials, energy or organisms, including people and other living things. It can also refer to the act of causing something or someone to become separated or isolated.
Normally, isolation requires barriers, or distance between that which is isolated and that which it is isolated from.
Barrier is anything that blocks or separates materials, energy and/or organisms in one space from materials, energy and/or organisms in another.
Containment is the process of isolating a space by placing barriers around that space, thus putting the space and anything in it into isolation.
Enclosure is a device or structure that includes barriers to provide some amount of isolation for the space within it.