A binary message format is a method of structuring data for communication between programs or systems using raw binary data instead of human-readable text. Unlike text-based formats such as JSON or XML, binary formats encode information in compact sequences of bytes, improving efficiency and reducing message size. This makes them ideal for scenarios where bandwidth or performance is critical, such as network protocols, embedded systems, or real-time applications. However, binary formats are not easily readable or editable by humans, and often require predefined schemas and specialized tools for interpretation. Security considerations include ensuring proper parsing to prevent vulnerabilities.