Which of the following statements about fingerprint-based positioning technology are true?

Fingerprint-based positioning technology is a method that uses the signal strength or phase difference of wireless signals to locate objects. There are two types of fingerprint-based positioning technology: virtual fingerprint-based positioning and real fingerprint-based positioning. In virtual fingerprint-based positioning, the positioning engine generates a virtual fingerprint library through calculations based on the AP deployment and environment information. In real fingerprint-based positioning, the fingerprint map is obtained through onsite information collection.