What is the difference between a reservation and a booking?

A booking: you request a space and the space need to confirm it. As soon as this is done, the booking is confirmed.

A reservation: you would like to put an option on the space: for that you are requesting the space, when the reservation is confirmed, you still have 3 days to take your final decision. 

Both types of booking can also be done on direct booking and direct reservation : this is when the venue is confiming the availability automatically.