binary format
A way of storing data as compact bytes instead of readable text.
Binary formats (postcard, bincode, MessagePack) are smaller and faster than JSON but not human-readable and usually not self-describing, so both sides must agree on the types and version.
Examples
postcard::to_stdvec(&r)?turns aReading { sensor: "porch", celsius: 21.5 }into 14 bytes with no field names, where the JSON is 33 bytes.
See also