Encoding vs Modulation

From http://forums.whirlpool.net.au/archive/397238

Modulation is the varying of a signal characteristic to convey data or information; usually the phase, amplitude or frequency are varied. The term modulation is applied to both analogue signals (AM radio, old-fashioned TV) and also to digital data.

When used to convey digital data, the way the modulation is applied is represented by a schema (or code, or map, or alphabet). FSK, PSK, ASK are all encoding techniques used by the modulating device to put the data onto the signal, where it is carried to the other end and demodulated… A value from a specific list or alphabet of possible values in the schema causes a specific modulation; and when demodulated the same value is received at the other end.

data -> encoded -> modulated signal -> decoded -> data. The signal varies with the type of modulation being used, the way the signal varies is the information.

Encoding has nothing to do with adding redundant information to data to increase the reliability of detection, as far as I am aware. Specific data encoding techniques can certainly add additional information to the signal to provide error detection and even error correction.