Domain pointers allow you to "point" or "park" additional domain names to your existing hosting account. This will allow users to also reach your website when entering the "parked" or "pointed" domain into their browsers.
For example: if you park 1domain.com at your hosting account for 2domain.com, users visiting 1domain.com will see the contents of 2domain.com web page.
You can park domain names from your control panel - Parked Domains section.