What is a GSM jammer? What is GSM signal?

What is the GSM signal, and is it related to the cell phone signal? Can cell phone jammers block GSM signals?

Topsignaljammer  2022.3

First of all, let me answer what is GSM signal: GSM signal is the 2G signal in our communication signal. Now most countries rarely use 2G signal, but we can still see it in our lives. Cell phone jammer can Shield 2/3/4/5g mobile phone signal, of course, can also shield GSM signal.