An OFDM symbol is a fundamental unit in Orthogonal Frequency Division Multiplexing (OFDM), a method used in digital communication. It consists of multiple subcarriers, each carrying a portion of the data. By spreading the data across these subcarriers, OFDM improves resistance to interference and allows for efficient use of the available bandwidth. Each OFDM symbol is generated by modulating the subcarriers using techniques like QAM (Quadrature Amplitude Modulation) or PSK (Phase Shift Keying). The symbols are transmitted in parallel, which helps to minimize the effects of multipath fading and enhances overall data transmission rates in systems like Wi-Fi and 4G/5G networks.