Islamic banks do not give cash money as loans, rather than they enter in a partnership with u as a customer, for example if u want to buy a car they will buy it instead and sell it to u in installments "they can charge u with higher price than the cash price since they r giving u the previlege of installments", which is called Murabaha..not interest. so if anytime u got money and u wanted to close the deal then u have to pay the total amount u agreed to pay in the beginning (total installments) while in the non islamic bank they will give u money and u have to return it back with interest, and if u decided to pay it back before the due date, they will not charge for the later period. I dont know how some people call it the same, it's like saying that adultry and marriage are the same since they consist of the same physical acts.!!!