Physics is a study of matter and its interaction at the fundamental level. Physicists seek to measure, understand, model, and control the processes in the physical world around us. To this end, physicists use a variety of descriptive and quantitative techniques to represent their knowledge. Furthermore, this work is conducted in a community where collaboration, teaching, and communication of results are essential. Applied physics makes a connection between fundamental research in physics and its application to real-world problem-solving. Research in applied physics has led to the use of electricity and magnetism for lighting and propulsion, given birth to the semiconductor industry that has provided us with the conveniences of modern electronics, and played an important part in the development of biomedical technology. While engineers have perfected many of these inventions, applied physicists have been responsible for their discovery.