Greenware is defined as unfired ceramics. It is clay that has been shaped and dried, but not fired in a kiln. Greenware is fragile and can break easily.
There are three stages of greenware: bisque, biscuit, and glaze.
Bisque is the first stage of greenware. The clay piece is dried completely and then fired in a kiln at a low temperature to harden it. Once bisqued, the piece is no longer fragile and can be handled without fear of breaking it.
Biscuit is the second stage of greenware. The bisqued piece is fired again, this time at a higher temperature to further harden it. Once biscuit fired, the piece can be glazed.
Glaze is the third and final stage of greenware. The biscuit fired piece is dipped in or sprayed with a liquid glass solution called glaze. After the glaze dries, it is then put through another firing process in order to fuse the glaze to the surface of the piece; this gives it a smooth, shiny finish..