The menu items people can see in the SharePoint library depend on permissions. Site owners assign people to SharePoint groups; each group comes with permissions to do certain things.
You just saw an animation that showed how you can edit a worksheet using the Edit in Microsoft Excel command, shown in the picture. But what if you want to prevent some people from editing the file? Is there a way to hide that command from certain people? Yes.
SharePoint permissions, granted by site owners, can determine if that command appears for someone or not.
People in the Owner and Member groups have permission to edit files in Excel. In SharePoint, these people can see the Edit in Microsoft Office Excel
People in the Visitor or Viewer groups do not see the Edit in Microsoft Office Excel
command, so they cannot edit SharePoint files.
The second course in this series, Excel Services II: Requirements, recommendations, and permissions explains permissions in more detail. You'll learn how to add people to groups so that some can edit files, while others can only view them.