No, it is adding a hyperlink for navigation. It is not a predecessor or successor. The hyperlink is to the Task ID. If the task ID changes, the hyperlink points to the original ID.

Right click select Hyperlink. Choose Place in this document. Enter the ID.

Control + Click on the Hyperlink indicator in the Indicator column to go to the Task ID.

I do not know of any other method to "relate" tasks to one another other than the methods I have already outlined.