Basic authentication is a method for a web browser or other client program to provide a user name and password when making a request.
Basic authentication was introduced with RFC1945 (HTTP/1.0) and is historically the first mechanism for authenticating at the HTTP layer level. Relying on base64 encoding, it is considered from the beginning as weak and unsecure, but it has a legitimate use on trusted connections (either on encrypted tunnels such as SSL, or unencrypted on a closed network).
Mechanism description :
When challenged by an HTTP server sending a WWW-Authenticate header with a realm challenge, the HTTP client must send a new request including an Authorization header containing the user's credentials encoded in base64.
The user credentials can be stored on the HTTP server itself, or on a remote system such as LDAP.