Building a project
Environment variable
Environment variables supply named configuration to a program. A .env file is one way to load them. They can hold ordinary settings or secrets; the variable name alone does not control who receives the value.
You might see: env variable, dotenv, .env
In a real project
Your local app and deployed app can read different database URLs under the same variable name. You configure each environment separately instead of editing the application whenever its destination changes.
A common mistake
Assuming .env makes a value private. Committing the file exposes its contents, and framework prefixes such as NEXT_PUBLIC_ allow values to be bundled into browser code.
Put it into practice
These lessons open through your account. Your kit determines which are available.
Go to the source
Sources checked .