It really depends if you have Wi-Fi or not.
The Pal Pad (Japanese: ともだちてちょう Friend Notebook) is a key item introduced in Generation IV and used again in Generation V. It allows players to register friends, who can be met in the Wi-Fi Club to battle and trade Pokémon. - Quote from Bulbapedia
It will store and show your Friend Codes allowing you to enter the Wi-Fi Club.
