What does HTTPS mean in a website address?

Hyper Text Transfer Protocol Secure (HTTPS) is the secure protocol through which your browser communicates with sites.
When using HTTP sites, any data that is transferred can potentially be accessed or manipulated by attackers. However, when using HTTPS sites, data is encrypted and authenticated and therefore secured.
We are committed to protecting your and your users data. Therefore, we are making it easy and free for your site to become HTTPS

Benefits of Using HTTPS

Your site visitors' information is encrypted, and therefore more secure.
Many users are more comfortable making purchases and sharing their personal information online when visiting secured sites.
Starting early 2017, Google Chrome will begin displaying warnings anytime that a user visits a site that is not using HTTPS. Therefore if your site is not secured, your site visitors will get a warning message anytime they access your site.
Google ranks HTTPS sites more favorably. Converting your site to HTTPS will therefore improve your Search Engine Optimization (SEO).

A Secure Sockets Layer, or SSL certificate, allows your site visitors to view your site over an HTTPS connection. It secures the connection between your browser and the site you’re visiting.
This will provide your site with an SSL certificate. You can see if your site has an SSL certificate if the URL begins with https:// instead of http://.
Your site URL used to display in a browser with an "i" icon to show that it had no SSL certificate:
Your site URL will now be displayed in a browser with a green lock icon to show that it has an SSL certificate:

Some older browsers don’t support the high security standards required by our SSL certificates.
Unsupported browsers include:
Google Chrome versions older than 6
Internet Explorer versions older than 7
Firefox versions older than 2.0
Safari versions older than 2.1
All versions of Internet Explorer on Windows XP
Unsupported mobile browsers include:
Safari browser running on an iOS version older than 4.0
Android browsers running on a version older than 3.0 (Honeycomb)
Windows Phone browsers running on a version older than 7