Engineers apply science to solve practical problems. There are lots of different kinds of engineering: aerospace, electrical, chemical, civil, mechanical, environmental, computer, and industrial are a few kinds. This means that different kinds of engineers have knowledge of different scientific fields. For example, environmental engineers apply much of the theoretical knowledge from environmental science.

Engineers don't design things and then see if anybody wants to use them. If they did, there would be a lot of creations that no one wants to have. Instead, researchers study the market (the people who might want what's going to be designed) to find out what they want and need. Because of this system, the products that engineers make meet people's needs or wants.

In their everyday work, engineers need to use a variety of skills. Their work involves a lot of creative problem solving. Their work is also interdisciplinary. This means that they apply the knowledge from many different subject areas, or disciplines, to their work. For example, a mechanical engineer could use knowledge of mathematics, physics, computers, and robotics. Engineers also need to know how to work in teams. In order to complete a successful design, engineers need to work with different people at different stages of the project.

When engineers are designing something, they often follow a Design Process. (This serves a purpose similar to scientists using the Scientific Method.) Different engineers may follow different steps, they may do some steps in a different order, or they may return to some steps more than once. Still, this is a common version of the Design Process:

1. Identify the problem.
   • What do people need or want?
2. Create criteria.
   • Criteria are guidelines or specifications that you decide on before you design something. Criteria are generally written as: "the ____, the better". For example, some common criteria might be "the simpler, the better", or "the cheaper, the better".
3. Design your product.
   • This is the main step. What will your product look like? How will it work?
4. Optimization.
   • Optimization is an engineering term that just means improving your design so that it better meets your criteria. Engineers have to watch out for something called suboptimization. This means improving one factor, but making the entire design worse.
5. Build a prototype.
   • A prototype is a model of your design. This lets the customers know exactly what they're getting. Engineers also often draw blueprints of their design for the same reason.

Engineers have achieved many remarkable things. In just the last 25 years, engineers have designed jumbo jets, lasers, computer microprocessors, and satellites. These and many more achievements have changed the world. In the future, it seems certain that engineering will continue to play an essential role.