16-QAM, or 16-Quadrature Amplitude Modulation, is a digital modulation technique that conveys data by varying the amplitude of two carrier waves. These waves are out of phase by 90 degrees, allowing for the transmission of four bits of data per symbol. This means that 16 different combinations of amplitude and phase can represent the data, making it efficient for high-speed communication. This method is commonly used in various communication systems, including Wi-Fi, cellular networks, and digital television. By increasing the number of symbols, 16-QAM can transmit more data in the same bandwidth compared to simpler modulation schemes, enhancing overall data throughput.