What is the real purpose of using a cell phone jammer?

Where will the cell phone jammer be used? In places where you want to ensure information security or where quietness is required, where cell phone signals are blocked, it is commonly used:

The VVIP movement has cell phone jammers in its vehicles and in the sites where VVIP exists. It can block remotely triggered bombs, etc.

The bank uses it in its main cash channel to prevent thieves from communicating with outside associates.

The conference center is tired of asking everyone to turn off their phones (which is easier to block the signal) and use it

In some professional examples, hospitals use it in CCU/ICU

The telecommunications authorities of some countries/regions have regulations on where and when to use cell phone jammers. Improper use of cell phone jammers can cause serious damage to the coverage map of cell phone operators.