How public is 'public'?

Hi,

I understand I have to set my calendar to public in order for people to see, after I have embedded it on my website (members area). But how public is public?
Does this mean (like with Google Calendar) that people will be able to google the appointments in my Zoho Calendar?
I need something like the 'hidden'-feature in YouTube, so that people can't find it, but are able to view it if they have the url. Is something like that currently posible in Zoho?

Thanks!
Jan