Question : Working of a SIM card

May I know How the Sim card works and where the data is stored? Is there any kind of block diagram for the working of Sim cards?

Where can i get more information related to this?

Answer : Working of a SIM card

http://pda.etsi.org/pda/home.asp?wki_id=11245

You will probably have to join the organization before you can download the actual file. But joining is free.