Target Parameter in Stage Precision are links/references to change values, select objects and more.
They can be found in different Filters, Morphes and other Parameters wich needs a link to an object or to a parameter.

If you click and hold down your mouse your target icon from your cursor will changed into a target cursor:

If you move the cursor now for example to an object inside the object tree, the inspector opens the parameter for this object.
Still keep the cursor pressed, and navigate now to any parameter inside the inspector and release the cursor if you are on top of the needed parameter.

You have now linked the target parameter.

You also can release the target cursor on top of an object wich will appears a menu with all paramaters from this object.

You can now navigate through the menu to choose a parameter wich will be linked into the target parameter.

If you release the target cursor on top of an interface element it will not only show the parameter menu, it will also get quick acces to the “most needed” functions.
Like on a button: “press Button / release Button”.