It's often important to know where a card exists. This is visualized with Relations. The card above shows you a summary of where this card currently resides. The relations are shown on cards by default but can be turned off in backlog and board show options.
If you click the card and go to More and Relations you will open the relations window.
In this view you get a clearer picture of what's going on with your card. In the boards section it will even tell you what column it's currently sitting in.