Purpose of the Pointer to Pointer

[Ajaycpp]

Hi,

Can anyone explain what is the purpose of the "pointer to pointer" and give any real time examples for that.

Thanks.

[mutexe]

google...
http://stackoverflow.com/questions/897366/how-do-pointer-to-pointers-work-in-c
http://www.eskimo.com/~scs/cclass/int/sx8.html
http://www.cplusplus.com/forum/beginner/337/