Domain Mapping for Dummies

Yesterday I was asked to describe what domain mapping was and it had me stumped. I knew it was different to domain forwarding (otherwise known as URL redirection or web forwarding) although I wasn't exactly sure how.

Domain forwarding (or web forwarding) is where you can have any number of different domains registered. They can all be pointed to the same website IP so that when you type in the URL of any one of those domains, the same website will be displayed, but the URL will retain the domain name entered originally. Some of the purposes of domain forwarding are:

1. To have similar domain names all pointing to the same website (e.g. try typing in www.gooogle.com)
2. So that you can move a website to a new domain and still retain the old domain
3. To have short, meaningful aliases instead of long, easily forgotton URLs

Domain mapping is different to domain forwarding because the permalinks and URL contain the address of your primary domain, even if you type in a completely different domain which has been 'mapped' to the primary one. So how is this useful?

For ecommerce sites it is invaluable as it means that you only have to pay for one SSL (secure socket layer) certificate: that of your 'primary' domain. You absolutely have to have an SSL to encrypt credit card transactions - shown by the little padlock symbol that appears at the bottom of the screen - but they don't come cheap so you don't really want to have to pay for one for each domain you own.

Domain mapping is also great for blogs. One example of where we have used domain mapping recently is for a client's blog. The blog portal is: www.blogmybook.com, and her full blog URL is: http://blogmybook.com/blogs/bliss_blog// - bit of a mouthful really. So, using domain mapping you can now enter bliss.blogmybook.com or www.blogmybook.com/bliss and still end up at the same place. And the cost - zilch. Magic!