Digital Certificates are issued and managed using a Certificate Authority or CA. In the market, there are two main types of CA systems that are explained in more detail in the Digi-CA™ Manual download or in the Managed CA – Digi-CA™ Service and CA Software – Digi-CA™ Server sub sections of the Certificate Authority online book.
Then there is the innovative CA combination that is unique to Digi-CA™ because of the principals used in the Core Design of Digi-CA™:
This unique offering is called the Shared CA: Digi-CA™ Shared
See the Digi-CA™ Flash Presentation that explains the design principals that have made this innovation possible.
So with Digi-CA™ there are in fact three types of Certificate Authority system to choose from: