Binary Phase Shift Keying (BPSK) is a digital modulation technique used in communication systems. It encodes data by changing the phase of a carrier wave between two distinct states, representing binary values 0 and 1. Each phase shift corresponds to a specific bit, allowing for efficient transmission of information over various media. BPSK is known for its simplicity and robustness against noise, making it suitable for applications like satellite communication and wireless networks. However, it has a lower data rate compared to more complex modulation schemes, as it only transmits one bit per symbol.