The external link option will allow you to add a link to your main menu which actually directs clients to a different website.
If you want to link to an external website you can do so in a few easy steps:
1. Go to Pages on the left menu bar in the control panel and click New bottom Page+.
2. Select External Link option at the top of the page.
3. Name the menu tab and add the URL for the site that you want to link to in the external link field and Save.
Congratulations! You have successfully added an external link to your page.