One of the features that SharePoint provides teams is the ability to share a calendar in SharePoint. This means that everyone can access and view the calendar directly from the SharePoint site via a web browser. What many are not aware of is that this same calendar can be linked to Outlook on a users desk. This linking can be accomplished with SharePoint on premise and via Office 365.
When you visit a calendar in SharePoint you can press the Calendar tab at the top of the page to expose the Ribbon Menu as shown. In the Ribbon Menu you will find a Connect to Outlook to button. Press this to connect this calendar to a local copy of Outlook on the desktop.
A security dialog will now be displayed. This is asking whether to be allowed to open content from the Internet (since in this example the SharePoint site is from Office 365). Press the Allow button to continue. Once allowed this prompt should not reappear.
Another security dialog may be displayed. This one is asking whether to allow content from the Internet onto the local computer through the inbuilt Windows Firewall (since in this example the SharePoint site is from Office 365 in the cloud). Press the Allow button to continue. Once allowed this prompt should not reappear.
The final security option will be to allow the calendar to connect to the Outlook application. This prompt appears because the request is to have Outlook to connect to external content. This prompt will be evident no matter which version of SharePoint in linked to. Press the Yes button to continue. Once allowed this prompt should not reappear.
You should now see the SharePoint calendar displayed side by side with the normal personal calendar. The linked SharePoint calendar is on the right and you can see it contains a single appointment.
If the SharePoint appointment is opened you will see in the lower part of the window that it is In Shared Folder Office – Calendar. This is an indication that the calendar is from SharePoint.
You will also notice a Copy to My Calendar button on the ribbon menu for this item. If you select this a copy of this appointment will be made to the users personal calendar. It is important to realize that this is only a copied appointment, it is no linked back to the SharePoint calendar in anyway. This means that if the appointment is changed in SharePoint those changes will not be reflected in the copy that is now in the users personal calendar. Likewise, if the user changes the copy of the SharePoint appointment in their own personal calendar that change will not flow through to the SharePoint calendar. Only the linked SharePoint calendar will reflect changes.
If however the appointment is changed in the SharePoint calendar that was linked (i.e. the calendar on the right previously) as shown above, then
that change WILL flow through to the SharePoint and to all users who have linked to the calendar as shown above.
Likewise, if the appointment is changed in SharePoint,
the appointment in the linked SharePoint calendar in Outlook will reflect that change, however
the version that was originally copied to the users personal calendar, as shown above, will not have any of the changes since it is not linked.
So, in summary, calendar linked from SharePoint are displayed as separate calendars in Outlook. Items can be copied from the synced SharePoint calendar to the users calendar but those items are not linked.