The plain-English version
A secret is sensitive information such as a private credential. An API key identifies or authorizes API use; some providers offer publishable keys as well as secret keys. Follow the provider’s rules for each key type.
Why it matters
Keep private credentials out of public browser code.
The docs behind it
Documentation links checked .
Editorial review · October 28, 2026
Corrected: Not every API key is a secret; Stripe explicitly distinguishes publishable, secret, and restricted keys.