Salt Water Chlorination
Salt water chlorination is a process that uses dissolved salt. The "chlorinator" uses electrolysis to break down the salt (NaCl). The resulting chemical reaction eventually produces hypochlorous acid (HOCl), and sodium hypochlorite (NaClO).  Sodium Hypochlorite is commonly used to disinfectant traditional pools.

Ultraviolet Disinfection
UV light is absorbed by the DNA in all living matter, or RNA in the case of a virus. The light causes cross bonds within the DNA structure to vibrate to the point of rupture. Once these bonds are broken, normal cell function quickly ceases. This process is accomplished in a tiny compartment attached to a pool pipe.