Introduction
A material is a substance of natural or artificial origin. Materials are defined by their origin (e.g. biological origin) and their properties, e.g. mechanical (flexibility or rigidity), chemical (water permeability or impermeability) or physical (electrical or thermal conductivity).
They are generally classified into several major families:
Metallic materials, including metals: iron, copper, bronze and metal alloys: stainless steel, etc.
Organic materials of biological, plant or animal origin: wood, cotton, paper, etc.
Minerals/inorganic materials: Rocks, ceramics, glass.
Plastics are generally obtained from fossil fuels found underground, such as oil.
Composite materials (e.g. carbon fibres) which achieve multiple properties by combining several materials from different families.