When we refer to interference when talking about entrance alerts, wireless doorbells, and driveway alarms, we are referencing nearby devices activating your products. A good example would be a wireless door chime ringing, you go to the door, and no one is there. Often times this happens when a nearby device, within range, is on the same frequency of your wireless device.
Privacy codes enable you to modify the frequency, eliminating this interference. This article covers, in detail, how to change the privacy codes on your wireless doorbells.