Definition
Plain language
The ready-to-run program file a computer actually executes, as opposed to the human-readable code it was built from.
As stated in the literature
Compiled machine-code artifact produced from source; because it is not human-readable, tampering in the binary (or in the toolchain that produces it) can be invisible to source review.
Also called: binaries
Why it matters: Because people review source code but computers run binaries, anything inserted after the source is written can ship to users without a single reviewer ever seeing it.
For example, the app icon you double-click is a binary — a file of machine instructions that looks like gibberish if you open it in a text editor, even though the code it came from was perfectly readable.
Heard on the show
“And on the audit side, the limitation they're most explicit about is that scaffolding is a knob, not a binary.”Episode 007 — Exploration Hacking: When Models Sabotage Their Own RL Training