A spring is stretched a fixed distance and the force it exerts as it returns to its relaxed shape is used as a standard. What is that force called?

1. Stretching a spring a fixed distance gives a reproducible force. 2. The force it exerts pulling itself back to its relaxed shape is called a restoring force. 3. The magnitudes of other forces can then be quoted as multiples of that standard unit. 4. A spring scale is one device built on exactly this idea. _Source: OpenStax College Physics (CC BY 4.0), Ch 4 "Dynamics: Force and Newton's Laws of Motion", section 4.1 Development of Force Concept_