# What is Environment Variable?

A value stored outside your code, like an API key or database URL. Your code reads it at runtime so secrets never get committed to a repository.

## In real work

Store the Claude API key as an environment variable in the secrets folder. Never hardcode it in a tutorial or a public repo.

## Related terms

- [Preview Deployment](https://prompthausapp.com/learn/preview-deployment.md)
- [ISR](https://prompthausapp.com/learn/isr.md)
- [Edge Network](https://prompthausapp.com/learn/edge-network.md)
- [Cold Start](https://prompthausapp.com/learn/cold-start.md)
- [Fluid Compute](https://prompthausapp.com/learn/fluid-compute.md)

## How is this different from Googling it?

Google gives a definition. Prompthaus pairs each term with how it shows up in standups, PRs, prompts, and design reviews—then quizzes you until the word sticks. One term a day on iPhone.

- Category: Launch
- HTML: https://prompthausapp.com/learn/environment-variable
- App Store: https://apps.apple.com/us/app/prompthaus-ai-vocabulary/id6776314407