Binary Phase Shift Keying, or BPSK, is a digital modulation technique used in communication systems. It conveys data by changing the phase of a carrier wave between two distinct states, representing binary digits (0s and 1s). This method is known for its simplicity and robustness against noise, making it suitable for various applications, including satellite and wireless communications. In BPSK, each phase shift corresponds to a specific bit value. For example, a phase of 0 degrees might represent a binary '1', while a phase of 180 degrees represents a binary '0'. This straightforward approach allows for efficient data transmission, although it has limitations in terms of data rate compared to more complex modulation schemes.