Absolute Threshold:The absolute threshold is the lowest level of stimulation that can be detected by a sensory system, such as the faintest sound you can hear or the dimmest light you can see.
Difference Threshold (Just Noticeable Difference): The difference threshold refers to the smallest amount of change in stimulation needed for an individual to notice a difference between two stimuli. For example, being able to tell if someone added one teaspoon or two teaspoons of sugar in your coffee.
Subliminal Stimuli:Subliminal stimuli are below our absolute threshold and therefore go unnoticed by our conscious awareness. They may still influence us subtly, but we are not consciously aware of them.