That is presumably for a Naturalisation application and no doubt you have added together £640 and £80 to get to your £720.
I stand to be corrected by I have seen no confirmation that the extra fee for the Citizenship Ceremony, currently £80, will indeed stay at that level. I think we shall have to wait and see about that.
UKBA quotes the two figures separately because if, exceptionally, an application is rejected, the unsuccessful applicant can actually get the Citizenship Ceremony fee back, because by definition, they will not be attending a Citizenship Ceremony.