Microwaves are generally considered to be a specific part of the wide radio frequency spectrum. The band from 300 MHz to 30 GHz is typically considered to be “microwaves,” for example by the Institute of Electrical end Electronics Engineers (IEEE), although many of us prefer to set the lower limit somewhat higher—perhaps at 1 or even 3 GHz. Above 30 GHz, the term “millimeter waves” is used. High school physics suggests that we are talking about wavelengths ranging from about 30 cm down to 10 mm.
