Synthesis Techniques concern means of producing sound, electronically or digitally, in which no physical acoustic source is used (except possibly as a model).
Resynthesis Techniques concern the modification of exisiting recorded or synthesised sounds, generally through the application of a computing algorithm to some form of computer representation of the sound. Frequently Resynthesis Techniques will involve the creation of a new 'output' sound based on the desired signal processing applied to the original 'input' sound.
For the purposes of the Subject Index, specific Synthesis/Resynthesis Techniques may be looked up under this umbrella term.