Secure Sockets Layer (SSL) protocol

The Secure Sockets Layer (SSL) protocol was developed by Netscape Communications Corporation.

SSL ensures the data that is transferred between a client and a server remains private. This protocol enables the client to authenticate the identity of the server.

When your server has a digital certificate, SSL-enabled browsers can communicate securely with your server, using SSL. With SSL, you can easily establish a security-enabled Web site on the Internet, or on your private intranet. A browser that does not support HTTP over SSL cannot request URLs using HTTPS. The non-SSL browsers do not allow submission of forms that require secure communications.

HTTPS represents a unique protocol that combines SSL and HTTP. Specify https:// as an anchor in HTML documents that link to SSL-protected documents. A client user can also open a URL by specifying https:// to request an SSL-protected document.

Because HTTPS (HTTP + SSL) and HTTP are different protocols and use different ports (443 and 80, respectively), you can run both SSL and non-SSL requests simultaneously. This capability enables you to provide information to users without security, while providing specific information only to browsers making secure requests. With this functionality, a retail company on the Internet can support users looking through their company merchandise without security, but then fill out order forms and send their credit card numbers using security.