Which term describes a complete lighting unit that includes a light source and parts for positioning and connecting it to power?

The term that describes a complete lighting unit, which includes a light source as well as components necessary for positioning and connection to power, is "luminaire." In the context of electrical and lighting terminology, a luminaire encompasses not just the bulb (the light source) but also the housing, wiring, and any additional structural elements that help in its installation and operation.

By definition, luminaires can be designed for various applications, from residential to commercial settings, and they often incorporate features for safety, efficiency, and aesthetic appeal. This makes the term particularly suitable for describing a complete lighting solution rather than just a part or an outlet.

In contrast, a lighting outlet typically refers to a point in the electrical system where light fixtures can be connected but does not imply a complete unit. A lighting fixture can be a loose term that may not encompass all the components of a luminaire since it might refer to just the part that holds the bulb. Furthermore, the term "assembly" is too general and does not specifically indicate that it pertains to a lighting unit. Thus, "luminaire" is the most precise and widely accepted term for this complete lighting unit.