The distinction between these two can be confusing since there are times when a label and event attribute can have the same name: the difference is in how they are used:
- Labels are used to sort and organize geofences into groups that will be helpful when building Places real-time push campaigns.
Example: "XYZ" store could use a label titled “San Francisco” that’s added to all geofences in San Francisco. When it comes time to build a campaign, rather than having to individually add every geofence in San Francisco, the marketing team at "XYZ" can just choose the San Francisco label and all of the geofences in that group are automatically added to the campaign.
- Custom event attributes are used to add details to a Places event tag that might be helpful during analysis or for user segmentation when building audiences off of historical Places data.
Example: A fast-food chain might have a custom attribute named “Restaurant Ownership” that tracks which franchisee owns each location.
OR
A fitness tracking app might have a custom attribute named “Event Type” added to each event geofence to show whether an event was a marathon, 5k, triathlon, etc. and build audiences based on which types of events a user has attended in the past.
To get a better background on Places & geofences read up on it here as well as more information on Messaging with Places.