Definition of channel

1. a radio frequency or communication path (e.g., a TV channel).
2. a high-speed data communication device used to interface IBM mainframe computers with input-output devices.
3. in desktop publishing, a set of images that will compose the final image when combined. The most common use for channels is the representation of the CMYK color separations in a paint program. Each color has its own channel.

   Sometimes channels can be used like layers in a draw program Selected areas can be saved to a new channel, manipulated separately from the rest of the image, and later recombined with the main channel.

4. a discussion forum in Internet Relay Chat or a similar service. See IRC; chat room.
5. a web page that is constantly updated, so that viewing it is like watching a television channel. See push (definition 2).

in technical analysis charting, the space, representing a trading range, between two parallel trend lines, one connecting the highs, the other connecting the lows in a price series. Channels can be ascending, descending, or horizontal, but the lines should be near parallel and, respectively, represent resistance level (top) and support level (bottom). A breakout in the opposite direction of either line may signify a trend reversal. Channels are used to guide short- and medium-term trading decisions. see illustration.