Dependency
ELI5 — The Vibe Check
A dependency is a package your project relies on to work. Your app depends on React to render UI, axios to make requests, and dotenv to read config. Pull the dependency out and that part of your app breaks. Everything has dependencies — it's turtles all the way down.
Real Talk
A dependency is an external package that your project requires to function. Listed in package.json, requirements.txt, or similar manifest files, they are installed via a package manager. Dependencies can be direct (used by your code) or transitive (used by your dependencies).
When You'll Hear This
"That feature adds three new dependencies — is that justified?" / "Audit your dependencies regularly for security vulnerabilities."
Related Terms
Lock File
A lock file is a snapshot of the exact versions of every package your project is using right now.
node_modules
node_modules is the folder where npm dumps all the packages you install. It can grow to hundreds of megabytes instantly and contains thousands of files.
Package
A package is a bundle of code someone else wrote and published so you don't have to reinvent the wheel. Need to parse dates? There's a package for that.
Semver (Semver)
Semver is the numbering system for software versions: MAJOR.MINOR.PATCH.
Virtual Environment
A virtual environment is an isolated bubble for your Python project's packages.