Buffer time gives your instructors time between appointments. If the service requires time to prep for the next appointment, this can be a helpful way to ensure your teachers have the time they need to prep and that your customers arrive to receive a high level of service. Essentially it ensures teachers cannot be booked back to back with no break in between.
Until recently, buffer time could be added only at the "board" level, meaning if you added 15 minutes buffer time there, that setting would apply to all appointments booked on that board.
You can now add specific buffer times per service type. To do this:
Click Appointments > Services > select a service > click Edit.
Scroll to bottom and add buffer time > Save Changes.