You see the following fields:

Company, Phone, Contact: Displays the company name, telephone number, and name of the principal contact for the vendor you are adding as an item supplier.
E-mail: Enter the vendor's email address, if any. If you are using a MAPI-compliant e-mail client (such as Microsoft Outlook), you can click the button to the right of this field to send e-mail to this vendor.
Web Page: Enter the vendor’s web page address, if any. If you have Internet Explorer installed, you can click the button to the right of this field to view the vendor's web page.