A number of the fields mentioned above handle campaign targeting. For more context, see the links below.
TargetingTo learn more about targeting - e.g. platform_targeting and publisher_targeting - see: Targeting Overview
Audience TargetingTo learn more about audience targeting - e.g. custom_audience_targeting - see: Audience Targeting Overview
Patching Publisher TargetingTo learn about patching the publisher_targeting field ,see: