What change in pigmentation of the skin is typically caused by exposure to the sun or ultraviolet light?

The change in pigmentation of the skin that is typically caused by exposure to the sun or ultraviolet light is a tan. When the skin is exposed to UV radiation, melanocytes in the skin produce more melanin, the pigment responsible for skin color. This increase in melanin production can lead to a darker skin tone known as a tan, which is the body's natural response to protect deeper layers of skin from UV damage. A tan indicates that the skin is trying to shield itself from harmful effects, and this process can vary in intensity based on skin type and the duration of sun exposure.

In contrast, sunburn is an inflammatory response resulting from overexposure to UV light, which can damage skin cells but does not necessarily produce a protective pigmentation increase like a tan does. Freckles represent a specific type of hyperpigmentation that occurs over time often influenced by genetics and additional sun exposure; they are not a direct result of ongoing UV exposure like tanning. Hyperpigmentation is a broader term that includes various forms of increased pigmentation in the skin, which can result from several factors, not limited to sun exposure. While hyperpigmentation might occur after sun damage, the immediate and typical response in healthy skin to UV exposure is the formation of a tan.