I won’t bother you on what makes them capable as opposed to not capable :)
Ballistic means they have no control over them once they’re launched? thanks
Ballistic is like a mortar or artillery shell. It’s destination is dependent on the trajectory in which it was launched.
The missile can have a trajectory that is for the most part ballistic, but the guidance does not end once the boost phase is over. Post boost phase guidance can range anywhere from a MIRV bus making course changes as it releases individual warheads (Trident, Minuteman III, SS-18) to terminal guidance (Pershing II). The Iskander may have such, possibly using the GLONASS (Soviet/Russian version of our GPS).