What term describes a guideline that remains fixed and does not move?

The term that describes a guideline which remains fixed and does not move is a stationary guide. This concept is crucial in hair cutting, where a stationary guide serves as a point of reference that helps create consistent lengths across the hairstyle. It allows the stylist to maintain uniformity and precision as they cut, ensuring that the resulting hairstyle has the intended shape and structure.

In contrast, a mobile guide is designed to change position as the cutting progresses, which allows for more versatility in styles and lengths. A static reference, while it might suggest stability, does not specifically pertain to the practice of hair cutting in the same way that a stationary guide does. Variable instruction implies changeability and adaptation, which is not the nature of a guideline that is meant to provide a constant reference point throughout the cutting process. Therefore, the correct terminology in this context is indeed the stationary guide, emphasizing its role in maintaining a fixed standard during haircuts.