Domains registered through ANA do NOT have to be hosted here. It's your domain! You own it so you're free to host your site anywhere you choose.

By default, your domain's nameserver's will be ours. In order to host your site elsewhere, you'll have to change nameservers. To do that, simply log in to your ANA account. In your client area, click on Domains to display the management options available to you. That screen will allow you to change nameservers in one simple step.