In the cellular world connections are supported on different bands. These bands correspond to a specific frequency and have specific characteristics with that connection. For instance, each connection has a supported bandwidth, such as 5, 10 or 20 MHz wide. To see the complete list of bands, frequencies, and channel widths refer to the following lists for 4G/LTE and 5G NR.
The Complete list of 4G/LTE bands and respective frequencies.
The complete list of 5G bands and the spectrum they use and channel width they support.