Environment variable & secret

Your site right now has no secrets — it is just pages anyone is allowed to see, so there is nothing to hide. But the moment you build something that connects to another service — a contact form, a login, anything that costs money or reads private data — you get a secret: a key or password that must never end up in your code. This short lesson teaches the one rule now, so it is a habit before you need it.

What a secret is