What is domain name forwarding?
Domain forwarding is similar to when a web page redirects a visitor to another website, but instead of using HTML or a script to do the redirection, the domain name itself redirects to the website. When a domain is set to forward visitors to another website, the domain name does not stay in the web browser's URL bar.
Why/when would I use domain forwarding?
Pointing a custom domain to a non-custom domain
If you launch your site with a non-custom domain and later choose a custom domain, you can use domain forwarding for this case.
Pointing one custom domain to another custom domain (multiple domains for a single site)
If you would like more than one custom domain to point to your site, you can use forwarding to point other domains to your main domain.
How do I forward my domain name?
Forwarding your domain name would be done at your domain registrar. Contact your domain registrar's support for assistance.
Here are instructions for GoDaddy: