Materials Science involves the design and study of solid materials and their properties based on composition and structure. Metallurgy is specific to the physical and chemical behavior of metallic elements. Composites are materials made of two or more different materials, while polymers are materials that have repeating units on a molecular level. We can optimize material selection based on factors, such as applied loads, cost, lead time, manufacturability, environmental factors, materials, and processes of compliance requirements, among others.