Magic byte

A magic byte is a specific, rarely used byte in a file or data stream that serves as an identifier, signaling the type or format of the file. Think of it like a unique signature or label at the beginning of a file, helping software recognize what kind of data it contains. For example, many image or video files start with a magic byte sequence that tells programs how to interpret the data correctly. This early marker ensures that systems can quickly identify and process files reliably without opening or analyzing the entire content.