Reflection coefficients are numerical values that describe how much of a wave is reflected when it encounters a boundary between two different media. They range from -1 to 1, where a value of 1 indicates total reflection, and a value of 0 means no reflection occurs. This concept is commonly used in fields like physics, engineering, and telecommunications to analyze wave behavior. In practical terms, the reflection coefficient helps engineers design systems that minimize signal loss, such as in fiber optics or radio frequency applications. By understanding how waves interact with materials, professionals can optimize performance and improve communication efficiency.