what is difference between short wave and medium wave

Short waves, radio waves whose frequencies range from about 3 to 25 megahertz (Mhz), corresponding roughly to the high-frequency band (see radio frequency). When they impinge on certain layers of the ionosphere, short waves are largely reflected back toward the earth. By one or more reflections between the earth and the ionosphere, a short-wave radio signal can be received at long distances from the transmitter. And medium wave or mediumwave (MW) is a part of the Medium frequency (MF) radio band used for AM broadcasting. For most of the world the frequencies used for broadcasting are from 520 kHz up to 1611 kHz, and in North America an extended AM broadcast band goes up to 1710 kHz. The band is sometimes referred to as the AM band, even though it is not the only frequency range to use amplitude modulation.