An orienting behavior which is non-directional. Here an animal reduces it's rate of movement, or increases its rate of turning, as the intensity of the stimulus increases (e.g. woodlice slow down, and turn more, in the dark). This action has the effect of keeping the organism in an area it finds favourable, and making it move away from areas it finds unfavourable.
An orienting behaviour which is directional. Here an animal turns towards, or away from a stimulus such as light. This can be positive or negative, positive would be turning towards the stimulus, negative away. Blowfly larvae (maggots) show negative phototaxis because they turn away from light.