The best way for your business to cash up at the end of each day depends on which figures you'd like to include.
If you'd like to include the value of all the Products sold, plus Reservations for today, then the Sales Report is the best option. The Sales Report includes all revenue in Sales that are dated today. Sales can be dated any date, for this cashing up method to work please ensure that all Sales are dated the date of the Reservation. This report may include payments that were not actually received today. E.g. this report includes deposits received on previous days for today's Reservations.
If you'd like to include only the Payments you actually received today, which may include deposits for future Reservations, plus Payments for today's Reservations and Products sold, then the Payments Report is the right one. The Payments Report reports payment transactions at the exact time that they were taken, like a statement. It's primarily used to reconcile payment terminals and bank / PayPal accounts.
The Reservations Report contains all the data relating to the Reservations. These revenue figures include the amounts noted on Reservations only and does not include actual Sales figures or Payments. E.g. if extra Products or Services are added to the Sale and not to the Reservation, they will not be included in the Reservations Report.
The help guide for each report explains how to filter the reports as well as an explanation of the figures