Vendoring

Definitions

The practice of copying third-party dependencies directly into a project's repository (typically in a vendor/ directory) rather than fetching them from a package registry at build time. This guarantees reproducible builds and insulates the project from upstream deletions or compromises, at the cost of repository bloat.
In plain English: Keeping a copy of all the external code your project depends on inside your own project folder, so you're not reliant on outside sources being available.
Example: "After the left-pad incident we started vendoring all our dependencies — we'd rather have a fat repo than a broken build."