13 · Environments & Packaging
package.json
A JS project's manifest
The small file at the root of a JavaScript project listing its dependencies, its version, and handy “scripts” (shortcut commands). The package manager reads it to know what to install.
Concrete example
“npm run dev” works because a “dev” script is defined in package.json.
Why it matters
The table of contents of a JS project; the lockfile pins the exact versions it names.