Hi Purps,
Your FQDN is whatever you type into your browser to hit your webpage, so it's probably set up with either your ISP (if you have a fixed IP address) or with a dynamic DNS provider of some kind.
In essance, when you go to a webpage using SSL (https), the webpage sends some information, called a certificate, to "prove" who it is. The name on the certificate needs to match what you entered into the browser otherwise you get a warning about certificates and, depending on the browser, you may not be able to proceed (some browsers allow you to ignore certificate errors).
This is to prevent websites spoofing each other and is designed to protect Joe Public from, amongst other things, internet scams.
When I hit a page like "
www.mybank.com", if the certificate says "
www.scambank.com" then the browser will complain and warn me. When you set up a website, you obtain a certificate from someone called a certificate authority (like Varisign) who confirm that you are who you say you are. If you create your own certificate (known as self-signing) then you get a warning (from your browser) that the certificate cannot be checked (a different error!).
If you are interested in the whole process, I can recmmend a book called "The Code Book" by Simon Singh, who explains it all VERY clearly!
I hope this helps.
