Environment Variables
also env vars · .env
Named values stored outside your code and read at runtime, used to hold configuration and secrets like API keys without hardcoding them.
Analogy
Like a sealed settings drawer your app reads from instead of writing passwords on the walls.
Why it matters
They keep secrets out of code and let the same automation or app run safely across dev and production.
In practice
You store an API key in a .env file as API_KEY and reference it in code instead of pasting the literal value.