There are lots of models of nebulizer out there, and each one is a little different from the others. This general guide to nebulizer parts will give you a basic idea of what makes a nebulizer system function.
Nebulizer compressor: The compressor is the base of the system. It pumps air into the medication cup to create a breathable mist.
Nebulizer cup: This is the reservoir where measured liquid medication goes.
Mouthpiece/mask: This is the opening through which the mist is inhaled. Most nebulizer sets come with mouthpieces, but masks are available for those who find them more comfortable or who have trouble wrapping their lips around the mouthpiece.
Tubing: The tubing delivers air from the compressor to the medication cup.
Tubing connectors: These connect the tubing to the compressor and nebulizer cup.
All manufacturers provide specific information about the nebulizers they make, so check your user's manual to learn more about your model. Also, check with your manufacturer for warranty and replacement information.