A water distiller is a device used to purify water by boiling it into steam and then condensing the steam back into liquid. This process removes impurities such as salts, heavy metals, microorganisms, and most chemicals. Distilled water is often used in laboratories, medical settings, and for appliances like steam irons where mineral-free water is required. Although effective, distillation is slower and more energy-intensive compared to other filtration methods.