Orthogonal Frequency Division Multiplexing (OFDM) is a digital modulation technique used in telecommunications to transmit data over a radio wave. It divides the overall channel into multiple subchannels, each transmitting data at a lower rate, which allows for efficient use of bandwidth and robustness against interference and multipath effects. OFDM is commonly used in Wi-Fi, LTE, and other wireless communication standards due to its ability to provide high data rates and reliable performance in a variety of environments.