The field of Materials Science and Engineering (MSE) researches all classes of materials (metals, ceramics, electronic materials, and biomaterials) from a unified viewpoint and with an emphasis on the connections between the underlying structure and the processing, properties, and performance of the material.
MSE grew out of the disciplines of metallurgy and ceramics and now includes polymers, semiconductors, magnetic materials, photonic materials, and biological materials. A materials scientist studies how materials react in different conditions (such as temperature and pressure) and understands that all materials can be approached from a common set of principles. Architects, civil engineers, toy companies, NASA, bio-medical research companies, and the data storage industry are all recent users of technologies that developed from research in MSE.
Most fields in science and engineering are concerned in some way with materials, but only the field of materials science and engineering focuses directly on them.
Check out some of the questions and answers in Ask an Engineer to learn more about materials science!