Ceramics are hard, brittle materials which are good electrical and heat insulators.
Examples are brick, concrete, china and pottery, glass.
They have giant covalent or ionic bonding. Many are oxides of elements and are therefore corrosion resistant. Glass was the first ceramic to be used because it occurs naturally as obsidian - a material formed naturally by volcanoes. Glass is a super cooled liquid . Ceramics are used in furnace linings, sparking plugs, other electrical insulators, oven ware and building materials, because of their hardness, electrical and heat insulating properties and resistance to chemical attack.