Which header is used for HTTP basic Authentication?

The header used for HTTP Basic Authentication is the Authorization header. This header carries the credentials (username and password) encoded in Base64. The format of the header is:

Authorization: Basic <Base64-encoded-credentials>

Here's how it works:

When a client attempts to access a protected resource, it sends the Authorization header along with the HTTP request.

The "Basic" keyword in the header indicates that Basic Authentication is being used.

The client encodes the username and password in Base64 format (e.g., username: password becomes a Base64 string), which is then placed after the "Basic" keyword.

The server decodes the Base64 string, verifies the credentials, and grants access if they are valid. This method should always be used over HTTPS, as the credentials are only encoded, not encrypted, making them vulnerable over insecure connections.