What radio equipment do pilots use to communicate with ATC?
https://en.wikipedia.org/wiki/Airband
emphasis added

As of 2012, most countries divide the upper 19 MHz into 760 channels for amplitude modulation voice transmissions, on frequencies from 118–136.975 MHz, in steps of 25 kHz.

A typical plane often has two communication radios, referred to as COM1 and COM2.
Each radio has an active and standby frequency. The pilot can listen to either radio, or both radios at the same time, but can only broadcast on a single radio.
There are often 2 navigation radios as well, NAV1 and NAV2, which can be tuned to VORs or other radio beacons, and the pilot can listen on those radios (typically for Morse Code IDs, Recorded Voice broadcasts, and occasionally, Voice-over-VOR ATC)