Dual mobile phone use abroad What does it mean?

Users questions:Abroad with a mobile phone network configuration should be chosen that best and most practical. Abroad can also use the more useful is what?
Experts answer: you can buy a candy bar of the machine, I'm the younger brother a few days before going abroad I bought the Nokia N72's to his department, he bought a number abroad can also be used.
  • This information provided by the users.Thanks!