Facebook business page-- Page name v. username?...

I've never used Facebook before and I'm trying to create a Facebook page for our company and I have what I hope is an easy question for someone in this forum.

On the Facebook page creation page:

[You must be registered and logged in to see this link.]

I plan to choose the option for 'Brand, product, or organization:' for our company. But just below this, there is a blank to fill in for 'Page name:'. However, in doing some research on this, Facebook apparently also has something called a 'username' for a business page. So, I'm confused as to what's the difference between these two.

There is no blank for 'Username' on the page creation page, so I'm concerned that if I enter the wrong name in the 'Page name:' blank, this could screw up the 'Username' that I want to secure for my company.

Ideally, I would like to copy what Amazon.com is doing with their Facebook page so that the Facebook page would show the name of the business as something like 'Amazon.com', but the URL for the facebook page would be something like '[You must be registered and logged in to see this link.]

If someone could point me in the right direction as how to set this up for our company, I would very much appreciate it.

Thanks in advance for your help on this.

Page's name is the one that will show up on Page's status updates, photos, videos, etc. Username is a short URL you can use to access your Page more easily (ie. [You must be registered and logged in to see this link.]FbookForum - the name of the page is 'FacebookForum v2.5, yet the username is FbookForum).

To choose an username, go to [You must be registered and logged in to see this link.] Note that your page must have at least 25 fans to do so!