A virtual number is a phone number that is not directly associated with a phone line. Virtual numbers provided by 8x8 can be programmed to send incoming calls to anywhere in your phone system, including extensions, voicemail, and the Auto Attendant (as well as Virtual Meeting and Virtual Fax if you are a Virtual Office Pro user). In addition, virtual numbers are useful for advertising numbers with area codes local to targeted callers. Multiple virtual numbers directed to the same destination can also be used to track which advertised phone numbers are generating the most call traffic, providing valuable analytics.
In contrast, a traditional telephone number is associated with a single, specific line at a single, specific location: your home phone number calls your house phone; the reservations number for the restaurant down the street connects directly to their front desk.