What's the difference between the HackerGuardian services?

HackerGuardian PCI Scan Compliancy

The PCI Scan Control Centre is an on-demand, vulnerability assessment scanning solution to enable merchants and service providers to achieve PCI scan compliance.

After each scan, users receive a comprehensive vulnerability report detailing any security issues with remediation advice and advisories to help fix them.

Following a successful scan (no vulnerabilities rated higher than CVSS
base score 4.0), merchants receive an official PCI compliance report that
can be sent to an acquiring bank.

The Standard version enables merchants to run 10 PCI scans per quarter on up to 5 IP addresses using the full complement of over 30,000+ individual vulnerability tests. The Enterprise version is a more powerful and flexible service which provides for up to 100 scans per quarter on 20 IP addresses.

HackerGuardian Free PCI Scan

The Free PCI Scan service is valid for 90 days and allows merchants to achieve PCI Scan compliancy free of charge. The service contains all the functionality of the Scan Compliancy but restricts the user to 5 PCI scans per quarter on a maximum of 3 separate IP addresses. The service generates an official 'PCI Compliant' report after every successful scan.