The 'Group ID' is meant to represent a logical grouping of Edge Nodes. This can be a region, a facility name, or any meaningful grouping of Edge Nodes within your application.
The 'Edge Node ID' is the ID of the logical Edge Node. This is often the name of the system running Ignition with MQTT Transmission
The 'Device ID' is the ID of a device attached to the Ignition instance. This can be a PLC or logical grouping of tags the represent a physical or logical device connected to Ignition.