Appointment lead time means that you can set a time that is always attached to an online booking. For example, if you have appointment lead time 24h, then customers can't make reservations for the current day (next 24h), even if there are free time slots on your calendar. PS! You can always add bookings to your calendar; it only affects the online booking page.
Scheduling window – works the same as previous, but now you can ask how far in advance you allow customers to book.
Permissions – here you can set which pages staff members have access to and which ones not.