Environment Variable

Definitions

1. A key-value pair set in the operating system's environment that configures application behavior without code changes. Used for secrets (API keys), feature toggles, and deployment-specific settings. The twelve-factor app methodology mandates storing config in environment variables.

   In plain English: A setting stored outside your code (in the server's environment) that your application reads at startup.

   Example: "Set DATABASE_URL as an environment variable — never hardcode connection strings in your source code."

Related Terms

• Environment Variable
• Config as Code
• infrastructure as code
• toil
• blast radius
• Auto-scaling
• Container
• DSC
• Secret
• CodeQL