There are times when it is beneficial to link points together so that they move together.
Select the parent point.
Select one or more points that will be linked to the parent. Note the parent is now blue.
All the points will change from a solid color to a gradient. This is your visual clue that these points are linked as you continue working.
Movement with Multiple Children
If you move the parent point, all the children points will move with it.
If you move one child, only the parent will move with it. The child points are linked to the parent, not the other children.