Sharing is optional. There are two web calendars you can share: a class roster and an availability calendar. Typically business that offer group classes (e.g. yoga, dance) use the first, and appointment based businesses (e.g. personal training, music) the latter.

You share the URL (web link) with your clients so they can view the roster on a web page in a browser on any device. The roster shows the scheduled classes with a big *Book* button.

For appointment-based business, you want to share your availability with your clients. They can do this with a web link that can be viewed in any browser on any device. It does not show your current bookings, just the empty spots they can pick.