Aging is a complex biological process in which cells become progressively damaged over time and eventually die. As we age, fewer and fewer cells are replaced, slowly wearing out our bodies.

This means that over time the damage accumulated in our bodies will become so immense, that at one point the body will not be able to cope with it - ultimately leading to our death. as: exposure to sun - "solar radiation", injuries, smoking, air and water pollution, etc., and genetics contribute to speeding up the process of aging as well. 

Aging affects our skin negatively by disturbing the normal function of skin cells. A majority of diseases are a result of aging. Our skin cells experience enormous amounts of damage on a daily basis. They are exposed to the constant bombardment of tens of thousands of harmful elements each day, causing irregular pigmentation (skin discoloration or hyperpigmentation) and loss of elasticity in the skin. 

Aging is involved in many other processes that such as accumulation of senescent cells, oxidative stress, immune and hormonal system changes.