Mobile signal repeater vs. mobile signal jammer 

Mobile signal repeater :

Purpose : to improve weak cellular signal in areas with poor coverage . 

Function : receives a weak signal from a cell tower ,amplifies it ,and retransmits it within a specific area . 

Legality : generally legal and widely used . 

Impact : improves cellular connectivity for users in the area . 

Mobile signal jammer :

Purpose : to intentionally block or interfere with wireless communication signals . 

Function : transmits radio signals on the same frequencies as mobile phones ,wi-fi,GPS,etc ,disrupting their operation . 

Legality : illegal in most contries due to its discruptive nature and potential for misuse . 

Impact : prevents communication ,creating a "dead zone" for wireless devices . 

In essence:

A signal repeater boosts a signal for better coverage . 

A signal jammer blocks signals to create interference . 

Important to note : the use of signal jammers is illegal in many countries ,as they can interfere with emergency services and other critical communications .