Page "Password" Paragraph 85

Transmission of the password, via the browser, in plaintext means it can be intercepted along its journey to the server.

Many web authentication systems use SSL to establish an encrypted session between the browser and the server, and is usually the underlying meaning of claims to have a " secure Web site ".

This is done automatically by the browser and increases integrity of the session, assuming neither end has been compromised and that the SSL / TLS implementations used are high quality ones.