What is a key difference between NM cable and conduit?

The key difference highlighted in the correct answer focuses on the construction and purpose of NM (Non-Metallic) cable compared to conduit. NM cable features a plastic sheathing that provides insulation and protection to the individual conductors inside. This design makes NM cable suitable for various applications, particularly in residential settings where ease of installation and flexibility in routing is needed.

In contrast, conduit is a protective tubing, often made of materials like PVC, EMT (Electrical Metallic Tubing), or rigid metal, designed to house and protect electrical wires from physical damage and environmental factors. Conduit allows for a more secure installation in situations where the wires might be exposed to potential hazards or when installing wiring in commercial or industrial applications.

Understanding these fundamental characteristics is essential for making informed decisions regarding wiring methods and systems in electrical installations. Each type serves distinct purposes within the National Electrical Code (NEC), influencing things like wire protection, installation environment, and application suitability.