A byte-oriented protocol treats the frame being transmitted as a sequence of bytes (characters) rather than as a raw stream of individual bits. Framing and control information are defined in terms of whole bytes — e.g. special reserved control bytes (like flag or escape bytes) mark the start/end of a frame, and byte-stuffing is used to escape any byte pattern within the data that would otherwise be misinterpreted as a control byte.

Examples: PPP (Point-to-Point Protocol), older protocols like BISYNC (Binary Synchronous Communication).

This contrasts with bit-oriented protocols (e.g. HDLC), which treat the frame as a raw sequence of bits and use bit-stuffing (inserting a single extra bit) to prevent a specific bit pattern from appearing accidentally within the data.