You can add a contact in either the "Contacts" tab, or while adding a location in the "Locations" tab.
When you add a contact to a location in the "Locations" tab, like a main office phone number, you are given the option of making the contact "Global," as seen below:
By making your contact "Global," the contact will be listed with both the location it is associated with in the "Locations" tab, and inside the "Contacts" tab. This can be troublesome if you have many contacts you wish to add.
For example, you have 10 locations with 3 contacts each that you want to add. If all these contacts are checked as "Global," your "Contacts" tab will have 30 numbers listed on it, which can be difficult or annoying for the app user to search through.
However, if you do NOT make a contact "Global," it can only be seen when the app user looks for a specific location in the "Locations" tab. There, they can see the contacts registered specifically for that location.
By picking and choosing which contacts you list as "Global," you can make it easier for your client to search for information in your app.