How does glaze differ from slip?

A slip (engobe) is a liquid mixture of clay and other materials suspended in water. Slip can be white or colored clay applied to a ceramic body to give it decorative color or improved texture. A glaze is used as waterproof layer which has been fused to a ceramic body through firing. Glaze is the last layer of ceramic that mostly serves to waterproof an item, but through multiple steps, it could also be used for decorating. Slip and glaze differ also in their composition. Slip has clay as dominant component in its mixture and the flux and glass former as auxiliary substance. The glazes are vice versa, with the flux and the glass former as predominant.