Significance of tag for sample data under graph classification

[vaastav]

Hi,
I noticed that multiple nodes for the sample data in a graph under the graph classification folder have the same tag. I was assuming tag meant the unique ID for that node but I guess not. Could you please explain what you mean by the tag in this scenario because I think that might be the cause of the issues I am seeing with my dataset.

[Hanjun-Dai]

that is the feature of the node