meray khiyaaal main database ki book se aik figure utha kr laga dena... or insan kisi se bhi pochay keh ess mian difference samja do yeah bht ghalat tareeqqa hai kisi bhi concept ko samjanay ka... ap ko chahe pehlay pooora data base mangement system parhain... or khud samjain... shortcut is longest way to reache the destination... ab mian aik tasveer laga doon.... out of context or logon ko kahin keh yeah mje samja do... tau main apni taraf se bht oncha ho jaon ga keh log kahian ke waah ji waah ji ... horror tau bht paraku hai ... yeah tau bht bara tipu sultan hai... ess kay sawalon ka jowab koi nahi de skta... yeah ghalat baaat hai.... Yeah sirf aik diagram hai jo ao Database ki book main milay gi.. ess mian koi rocket science nahi hia...