Secret
A secret is any code or password that must stay private, like an API key or a database password.
In a simple example
The key that lets your app talk to the AI service is a secret. The name of your shop is not.
Why it matters to you
If a secret leaks, others can act as you, and fixing it costs time and sometimes money.
Do not confuse with
A secret is not just any private file. It is something that gives power to whoever holds it.