Package (dependency)
A published unit of reusable code that projects install and build on, distributed through registries like npm or PyPI.
What it tells you about a developer
Publishing packages that others install is public, checkable proof of code quality. Choosing well-established packages, where a solution already exists, is itself a mark of professional judgment.
Packages are how the developer world shares code. When a project lists a package, that package is one of its dependencies. Registries record download counts, and they record which other projects depend on a package. That makes package authorship one of the most verifiable claims on a profile.