In residential wiring, what does 'sheathing' refer to?

Sheathing refers to the outer covering that encases a wire assembly, often serving several vital functions. It provides physical protection for the individual conductors inside, safeguards against environmental factors such as moisture and abrasion, and helps in maintaining the integrity and safety of the entire wiring system.

Understanding this concept is crucial because sheathing is a key component in ensuring that the system complies with safety standards and can operate effectively over time. While the insulation around individual wires is also essential, sheathing encompasses the entire assembly and includes any outer layers that provide added durability and protection. Additionally, it is distinct from the connections to the electrical panel or types of electrical conduit, which serve different purposes in the electrical system.