Electrolysis
Electrolysis is the process of dividing water into fractions, separating hydrogen from oxygen. This is achieved by an electrical field, pulling the negative charged hydroxide ions OH- to the positive electrode and the positive charged hydronium ions H3O+ to the negative electrode. When arriving at the electrodes the ions are discharged and become gaseous oxygen and hydrogen respectively.
Technological usage
Water is considered a natural resource on Mars. Electrolysis can be used to produce oxygen as part of air in artificial habitats. The produced hydrogen on the other hand can be used for hydrocarbon synthesis, yielding synthetic materials for space suits etc.