Erogenous zones are patches of skin that when stimulated that elicit a sexual response. There are two areas that will arouse a person sexually, the specific and nonspecific zones.
The specific zones are; the lips, nipples, penis, and vulva. Only in these areas will the body produce a high arousal response rate to an action potential in virtually everyone. The nonspecific erogenous zones do not produce such a heightened degree of sexual stimulation across the board. An exaggerated, or anticipatory response is responsible for the heightened sense in these areas, and not because there is an increased amount of touch-sensitive receptors like in the area of the specific zones. In addition, everyone has different nonspecific zone that are going to be active, a person might have only one or two "hot spots", or zero depending on the person.
Some of the more common examples of nonspecific spots are; Ears- The earlobe and behind the ear. Neck- The clavicle and the nape of the neck. Wrist- The area connected to the palm. Navel- Near and around the belly button and especially below it. Waist- On the sides up to the ribs and the small of the back. Legs- On the inner thigh, behind the knee, along the calf, and around the ankle. Feet- Bottoms of the feet and toes.
Our brains are very powerful organs, and the most powerful erogenous zone is a person's imagination, making it possible for stimulation achievable outside of direct contact by visual and conversational stimulus without ever being touched.