How was carry forward curreny option works? How does it differ from Intraday currency trading? Please explain!

Today I have placed a currency trade order for GBP/INR and placed in carry away category ? While ordering I was told that no additional charges will be levied for doing this type of transaction? but in debit section I could see a amount of money is debited under loss category even though I didnot sell today?

Suggest you to read futures module here: http://zerodha.com/varsity/

All futures positions are marked to market everyday. So as on the closing price of the day, if there is profit it is credited and if loss debited from your account.

Next day all profit and loss is now calculated based on this closing price.