On the Web tab, you can link any resource on the Web by entering its URL. The output code is generated as the <a> HTML element:
<a href="http://www.kentico.com">Kentico Software</a> |
On this tab, you can specify the same properties as described here, with the difference that the content of the General tab is displayed above the two other tabs.
Page url: http://devnet.kentico.com/docs/devguide/index.html?wysiwyg_insert_link_web.htm