A news article from Newsweek referenced the Center’s work.
As their name implies, ballistic missiles follow a trajectory that is determined by gravity. According to the Center for Arms Control and Non-Proliferation, ballistic missiles are first powered by a rocket or a series of rockets (launch phase), then arch upward unpowered (midcourse phase) before falling to hit their target (terminal phase). After its fuel has run out, the missile follows an elliptical orbit, which is determined by the velocity and flight angle and the Earth’s gravity, according to the Missile Defense Advocacy Alliance (MDAA).
Cruise missiles, on the other hand, are propelled by jet engines and use terrain mapping, GPS and inertial guidance to strike, according to the Center for Arms Control and Non-Proliferation. Flights can be preprogrammed, although operators can manually guide the missiles. Cruise missiles also usually stay inside the Earth’s atmosphere, making them harder to detect.