Waveguides are structures that guide electromagnetic waves, such as light or radio signals, from one point to another. They are typically made of materials like glass or metal and come in various shapes, including rectangular and cylindrical. By confining the waves within these structures, waveguides can efficiently transmit signals over long distances with minimal loss. These devices are essential in many technologies, including fiber optics for internet communication and microwave ovens for cooking. Waveguides help ensure that signals maintain their strength and clarity, making them crucial for applications in telecommunications, radar systems, and medical imaging.