This action aims to select the attribute based on the value of which objects in the System will be identified. It sounds complicated, but to put it in simpler terms:
If we have a layer with favourite restaurants’ locations and one of the attributes is the name, after setting the name as a Descriptive Attribute, we will see the name instead of the default ID at the top of the Object Card.
If possible, the Descriptive Attribute should be unique and not be empty (i.e. you should not select as Descriptive the attribute that perhaps will not be completed for each individual object, i.e. left as NULL).