NAV Extensions - Extension Management - Publish, Synchronize, Install. Compatibility and duplicates.

https://docs.microsoft.com/en-us/dynamics365/business-central/dev-itpro/developer/devenv-how-publish-and-install-an-extension-v2

• Publish
• Adds the Extension to your Extension Management List on the server
• Unpublishing removes the extension and ALL data associated with it
• Synchronize
• Synchronizes to the schema
• Must be done to allow install
• Synchronize in Clean mode will remove all versions and data for the extension
• Install
• Enables the extension for use in the current tenant/company
• Uninstall removes the functionality from the tenant/company, but retains the data 

• An extension is identified by it's ID in the app.json when you create a new project from View>Command Palette>AL:Go!
• "id": "d759b508-4de7-440a-8c2d-1d37267ea925",
• You cannot use object names or id's that already exist, or have already been used by other extensions
• When attempting to publish to the server, it will check that none of the object names or id's already exist for existing extensions
• If any objects already exist, publishing will fail, and Visual Studio code will indicate the duplicated objects
• Extensions will work with CAL modifications, however CAL modifications will not be able to interact with any Extension objects