Offset agreements often involve trade in military goods and services and are alternatively called: industrial compensations, industrial cooperation, offsets, industrial and regional benefits, balances, juste retour or equilibrium, to define mechanisms more complex than counter-trade. Counter-trade can also be considered one of the many forms of defense offset, to compensate a purchasing country.[3] The main difference between a generic offset and counter-trade, both common practices in the international defense trade, is the involvement of money. In counter-trade, goods are paid through barters or other mechanisms without the exchange of money, while in other defense offsets money is the measure and the medium of exchange.