I could see below description for both PCI External IP scan vs Web Application Scans
PCI External Network Scans
The Network section is where you manage your quarterly external network scans, per PCI DSS v3.0 requirement 11.2.2.
PCI Web Application Scans
The Web Applications section is where you manage scans of your public-facing web applications and review detected vulnerabilities, per PCI DSS v3.0 requirement 6.6.
My Question is what is the basic difference between these two ? Is there any possibility of overlapping of vulnerabilities if we do the external IP and web Application scans if we do ?