Glass is a versatile material made from natural raw materials that is used in many different areas. There are numerous types, shapes and sizes. For example, very thin sheets of glass (less than a millimetre thick) are used in electronics or medical technology. Huge glass panes are used in observatories, for example. Large glass fronts decorate modern building facades. We are all familiar with displays, lights, lenses and fibre optic cables from our everyday lives.