CRM Sync

Hi

I'm working in a B2C environment and I'm a little confused with the Zoho CRM sync feature in Zoho Invoice. I would expect that it would sync to my Contacts (converted Leads) and create new Customers in Invoice yet none of my contacts are imported.

Can you please help me to understand the relationship between the two applications and their modules. I checked the user manual and help documents, but couldn't find anything.

Thanks,
Gregg