Final answer:
A compression nut, compression sleeve, and a ferrule are parts of a compression fitting, which is used to join pipes or tubes in plumbing or electrical conduit systems without soldering.
Step-by-step explanation:
The components listed in the question—a compression nut, a compression sleeve, and a ferrule—comprise a compression fitting. A compression fitting is a type of connection used in plumbing and electrical conduit systems to join two pipes or tubes. This type of fitting usually consists of three parts: the compression nut, the compression sleeve (also known as a ring or ferrule), and a fitting body. The ferrule is placed around the pipe, followed by the nut which, when tightened, compresses the ferrule onto the pipe creating a watertight seal. This makes compression fittings a popular choice as they do not require soldering, thus they are relatively quick and easy to use, and they can be applied in confined spaces.