Moisturisers are combinations of chemicals that come together to help moisture the external layers of the skin. Moisturing the external layers of the skin makes it softer and smoother. The purpose of moisturisers are to increase the amount of water in the skin by reducing the amount of evaporation that occurs.
The skin does produce it’s own moisturisers in the form of naturally occurring lipids and sterols. The actions of these chemicals are often simulated in the creation of moisturisers.
There are, in fact, two ways in which moisturisers work.
The first method is by behaving as a Occlusive. An Occlusive works by creating a film on the surface of the skin to help stop the loss of moisture in the skin.
The second way is by acting as a Humectants which attracts moisture to the skin.