PSK, or Phase Shift Keying, is a digital modulation technique used in telecommunications. It conveys data by changing the phase of a carrier wave, allowing for efficient transmission of information over various media, such as radio waves or fiber optics. PSK is commonly used in applications like satellite communication and wireless networks. There are different types of PSK, including BPSK (Binary Phase Shift Keying) and QPSK (Quadrature Phase Shift Keying). Each type varies in the number of phase shifts used to represent data, impacting the data rate and robustness against noise. PSK is valued for its efficiency and reliability in transmitting digital signals.