Your employees and their working hours are the basis of your calendar. You can only enter appointments or offer online booking for customers if you have also added your employees to the calendar.
Employees in the calendar
Your employees are displayed in the calendar:

Employees in online booking
Your employees are displayed to the customer in online booking:

Resources (equipment and rooms)
In gyms, beauty studios and many other industries, equipment or rooms are often required that must be blocked in parallel with an appointment. These can also be added to the calendar to prevent double bookings.
Example of a calendar with employees and blocked rooms and equipment:

Articles on employees
Articles on rooms and equipment
Resources are equipment or rooms that are blocked at the same time as certain services to avoid double bookings.