Badge scanning is reading the barcode, QR code or chip on an attendee badge to record a check-in, a session entry or an exhibitor lead.
Scanning a badge at the entrance records event check-in. Scanning the same badge at a session door records session attendance. Scanning it at a booth creates an exhibitor lead. The gesture is identical and the data lands in three different places, which is why badge scanning is usually named by what is being recorded rather than by the act itself.
The scan does not read data off the badge. It reads an identifier and looks up the attendee record, which is why the information an exhibitor receives depends on what the attendee agreed to share at registration rather than on what is printed on the badge. It also means a reprinted badge works immediately, because the identifier follows the record.
Exhibitors want contact details. Attendees want to control who gets them. The registration form is where that gets settled, and it is worth settling explicitly, because an exhibitor who scans a hundred badges and receives a hundred names with no email addresses will report that lead capture did not work.
Attendees are checked in by scanning a QR code through the Admin App or at a kiosk, and sessions can be scanned at the door using their own session QR codes. Exhibitors scan a badge through the attendee app to see the attendee's basic information and add them as a lead. Events running RFID badges do the same things by tapping the badge rather than scanning a printed code.