Montages are specific arrangements of channels; a channel is a pair of electrodes. Waveforms result from cerebral potentials; each montage allows the reader to appreciate the same waveform through a distinct point of view. Bipolar montages consist of channels with adjacent electrode pairs. Referential montages consist of channels with nonadjacent electrode pairs. One electrode is located closer to the cerebral activity (active), while the other is intended as a distant reference (inactive). Common bipolar montages include the longitudinal bipolar (double banana) and transverse bipolar. Common referential montages include contralateral and ipsilateral ear reference, central reference (vertex), or average reference. Bipolar montages are less prone to artifact and best appreciate focal potentials. Referential montages are more prone to artifact and best appreciate broad or generalized potentials. An active reference results when the reference which is intended to be neutral is very active. The reader must use both types of montages to evaluate the same waveform. Digital displays make it easy to switch between montages.