explain deeply about foreign exchange?

You can refer to the given links to know about foreign exchange.

https://www.meritnation.com/ask-answer/question/give-the-meaning-of-foreign-exchange-and-foreign-exchange-ra/economics/3133685

https://www.meritnation.com/ask-answer/question/give-the-meaning-of-foreign-exchange-and-foreign-exchange-r/economics/7322657

If you are still left with any doubt, do get back to us.