A source or sender is one of the basic concepts of communication and information processing. Sources are objects which encode message data and transmit the information, via a channel, to one or more observers (or receivers). In the strictest sense of the word, particularly in information theory, a source is a process that generates message data that one would like to communicate, or reproduce as exactly as possible somewhere else in space or time. A source may be modelled as memoryless, ergodic, stationary, or stochastic, in order of increasing generality.
