What is a non-metallic sheathed cable commonly referred to as?

A non-metallic sheathed cable is commonly referred to as Romex. This term is actually a brand name owned by the Southwire Company, which has become synonymous with this type of cable among electricians and contractors. Romex is constructed with insulated conductors encased in a non-metallic sheath, commonly used in residential wiring applications due to its flexibility, ease of installation, and suitability for dry locations.

The characteristics of Romex cable include its non-metallic outer sheath that provides durability and insulation while protecting the copper or aluminum conductors inside. It's designed for use in various residential electrical systems and adheres to NEC (National Electrical Code) standards for safe installation.

While other cable types listed have specific uses and characteristics, they do not match the definition of non-metallic sheathed cable. Type AC cable typically has an armored sheath and is used for different applications, while BX cable often refers to metal-clad cable which is not specified as non-metallic. Luthier wire is unrelated, as it pertains to stringed instrument construction and has no relevance in electrical applications.