Answer to Question 1
Answer: These are earthenware, made of porous clay and fired at low temperatures and glazed; stoneware, fired at high temperatures and impermeable to water, used as dinnerware today; and porcelain, made with a smooth-textured clay fired at the highest temperatures to become extremely glossy and virtually translucent.
Answer to Question 2
Answer: After a first firing, the object will be painted with a glaze composed of powdered minerals suspended in water. After a second firing, the minerals dissolve and fuse into a coating that bonds to the clay and gives the object a glassy appearance. The glazing can also be used to produce colors.