2. Cash: Cash refers to free transactions in the international financial market, also known as "free foreign exchange". Foreign exchange widely used in international settlement and payment and freely convertible into other countries' currencies. The countries that issue these currencies have loose foreign exchange control and control, and some have even basically abolished foreign exchange control, while some countries have strict foreign exchange control, so their currencies cannot be freely converted into internationally used foreign currencies.

3. Cash: Foreign exchange cash is concrete and solid foreign banknotes and coins. When customers want to transfer cash abroad, they can bring cash or remit money. However, when customers use "remittance", because cash is in kind, the bank must transport it abroad, and the transportation expenses will be borne by the customers, which is manifested as "selling cash to buy cash" (customers sell cash to buy cash). It can be seen that cash cannot be converted into cash. If cash is converted into cash, customers will suffer some losses in foreign exchange amount.