Templates allow you to define groups of properties that can be applied quickly to events or sources.
Templates make it much easier to manage complex tracking plans as you don't have to keep adding the same properties to events multiple times. When you update a template, it applies the changes to all events or sources it's associated with.
For example, a music app might have a Song template that can be associated with all song-related events that include the following properties:
To add a template to an event, select the event, and you'll see a templates field. Once you've added the template the template properties will show up in the tracking plan for that event. To modify the properties for a template, simply navigate back to the template and make your changes; they'll be applied across all events or sources.
It's pretty common to capture source-specific context, such as
appVersion for iOS and Android sources. Once you've created your template you can apply it to a Source by navigating to Overview and adding it to the templates field for the appropriate source. These template properties are included on all events sent from that source.