What is the impact of 4800 and 9600

Dear all,
Someone can explain me the importance of this, related the my localisation and provider?
I ma using a swiss provider and not US.
Does cell.begin(9600) can make a issue if the Euripean bamn is 1800?

Could you calrifie the imprtamce of this?

many thanks

  //Initialize serial ports for communication.

These values refer to the baud rate (bits per second) of the serial port modules, i.e. the rate of communication from your arduino chip to your GSM shield (assuming that's what you're doing with "cell") and your pc ("Serial"). It is not related to your locality or provider, only the way your arduino chip connects to the shield.