GSM Shield and GSM modem

Can someone please help me? What is the difference between a GSM Shield and a GSM module? Thanks in advance.

A shield is a circuit board that plugs directly into your Arduino. A module usually doesn't so is (slightly) more complicated to connect. However, shields have their own problems with potential pin conflicts if you are using more than one shield.

Thank you for your reply, it helped me :smiley: