These are relations that are set up before the beginning of the animation. We will use a stickman figure and a basket ball as example figures.

Let's put the ball in the left hand of the stickman. Select the basket ball, choose "Containers" category and select the left hand container of stickman.
Notice that the ball "jumped" to the right hand of stickman. It is always best to set up the start relations before placing the figure with matrix tool.

To remove the relation, click the "X" button.