"Virtual hosting" means hosting multiple web-sites with different domain names on the same IP address.
From the "Internet Information Services (IIS) Manager" window, right click on a web-site, and select "Edit Bindings...":
In the "Site Bindings" dialog, select the first item, and click the "Edit" button:
Enter the web-site domain name in the "Host name" field:
Click the OK button in all the dialogs to save your changes.
Create additional web sites the same way.
For more information, please see the following knowledge base article: