CWDM (Coarse Wavelength Division Multiplexing) and DWDM (Dense Wavelength Division Multiplexing) are key technologies in optical communication. CWDM offers a relatively simple and cost-effective way to multiplex multiple optical signals over a single fiber, using a wider spacing between wavelengths. It is suitable for applications with moderate bandwidth requirements. On the other hand, DWDM provides much higher capacity by densely packing a large number of wavelengths onto a single fiber, enabling extremely high data transmission rates. DWDM systems require more sophisticated equipment and are often used in backbone networks and high-capacity data centers. Both technologies play vital roles in meeting the ever-increasing demand for bandwidth in today's digital age. 😊