Final answer:
Weber's law states that the difference threshold is a constant proportion of the original stimulus, and it refers to the minimum amount of difference in stimuli required to detect a change between them.
Step-by-step explanation:
Weber's law states that the difference threshold, also known as the just noticeable difference (jnd), is a constant proportion of the original stimulus. The difference threshold refers to the minimum amount of difference in stimuli required to detect a change between them. It is not a constant quantity; instead, it changes depending on the stimulus intensity. For example, in a dark movie theater, a small change in illumination from a cell phone screen would be easily noticeable, but the same change in a brightly lit arena during a basketball game would not be easily detectable.