The differences lie in channel spacing, wavelength range, capacity, reach, and cost. In fiber-optic communications, wavelength-division multiplexing (WDM) is a technology which multiplexes a number of optical carrier signals onto a single optical fiber by using different wavelengths (i. This allows multiple channels of data to be transmitted simultaneously. By comparing CWDM vs DWDM vs MWDM vs LWDM vs SWDM, you can make an informed decision to ensure your network meets your data capacity, distance, and application requirements. Read on to learn the fundamentals of this useful technology.