There are many different ways that you can divide up the field of engineering, and so there is no single answer to this question. However, one commonly used denomination breaks engineering down into four distinct fields. Those are: Chemical engineering Chemical engineers use knowledge of chemistry, mathematics, biology, and other sciences in order to create products and ensure safety throughout society. They may help design food production processes and help calculate the necessary inputs to create different products. Civil engineering  Civil engineers focus on infrastructure. That includes our public water systems, our roads, highways, and bridges, our internet and phone lines, and more. All of those things that make our society function and that many people have come to take for granted, were probably designed by a civil engineer. Electrical engineering  Electrical engineers specialize in the design of everything electrical; motors, circuits, and other pieces of electrical devices are their specialties. This could include designing computers, telephones, TV"s, and larger things such as power grids, medial equipment, and more. Mechanical engineering Mechanical engineering is an extremely broad subfield, and has significant overlap with electrical engineering. These engineers specialize in designing machines, which can take all sorts of shapes and sizes. They even design the machines that we use to build other machines. This field has huge breadth and students can take it in a host of different directions as a career.