HTTP is meant to run over a bidirectional tunnel for arbitrary binary data; when that tunnel is an SSL/TLS connection, then the whole is called "HTTPS".
"SSL" means "Secure Sockets Layer".
"TLS" means "Transport Layer Security".
The name was changed to avoid any legal issues with Netscape so that the protocol could be "open and free" (and published as a RFC).
"HTTPS" is supposed to mean "HyperText Transfer Protocol Secure",
Other protocol acronyms have been built the same way, e.g. SMTPS, IMAPS, FTPS... all of them being a bare protocol that "got secured" by running it within some SSL/TLS.
To make the confusing perfect: SSL (secure socket layer) often refers to the old protocol variant which starts with the handshake right away and therefore requires another port for the encrypted protocol such as 443 instead of 80.
TLS (transport layer security) often refers to the new variant which allows to start with an unencrypted traditional protocol and then issuing a command (usually STARTTLS) to initialize the handshake.
Whether you use SSL or TLS for this depends on the configuration of your browser and of the server (there usually is an option to allow SSLv2, SSLv3 or TLS 1.x).