Optical networks are communication systems that use light to transmit data over long distances. They rely on fiber optic cables, which are made of thin strands of glass or plastic that carry light signals. This technology allows for high-speed data transfer, making it ideal for internet, television, and telephone services. These networks utilize various components, such as lasers for generating light and photodetectors for receiving it. Optical networks can support a large amount of data simultaneously, which is essential for modern applications like cloud computing and streaming services. Their efficiency and speed make them a crucial part of today's communication infrastructure.