Dear Ranjeet,
F-47 is used to generate request so that actual down payment can be posted to Down Payment request. This is again business decision to have this process or not. Some business follows process to post down payment with reference to "Down Payment Request" via this you can have track and control on business accounting.
F-47 is just request ( Also called as "Noted Item" ) to post a down payment in system. This request will create a document number and accounting department further will process the request. Since this is just a request it will NOT have a financial impact.
I hope this will give you fair understanding, if having any doubts please get back to forum for further assistance.
Thank you.
Regards,
Pankaj Bhalerao.