Disturbance to the normal or expected operation of electrical or electronic devices, equipment, and systems. Electrical interference is sometimes called radio-frequency interference (RFI) or electromagnetic interference (EMI). Such disturbances may range from nuisances (for example, an electric shaver jamming a nearby broadcast radio receiver) to catastrophes (for example, midair aircraft collision due to EMI navigation errors in holding patterns during bad weather in terminal areas). Electrical noise is a broader term that includes those phenomena that are generally termed electrical interference, but also includes naturally occurring currents or voltages that are more or less continuous and cannot be completely eliminated.