abbreviation for "id est," Latin
for "that is"; also means, "in other words." it is followed by an explanation, specific list or a paraphrase.
compare with e.g.
also reference: www.getitwriteonline.com/archive/061801.htm, another comparison of i.e. and e.g.
i like music (i.e., the ordering of tones or sounds to produce rhythm, melody and/or harmony.)