A first overview has its origin in the score, the ready-to-hear sound object:


Several tracks form a score. The track consists of fitted sources. Track and likewise score can be processed by effects.
The source can be a sample (a normally recorded sound) or a synthetical (artificial) sound. 
Synthetical sounds can be produced by numerous means.
One of these, Additive Synthesis, has its advantage in being performed by only three parameters. Frequency, velocity and phase of an oscillator are sufficient to form one partial sound.
For other forms of synthesis look on other forms. Partially the factory denominations are chosen badly and sometimes even wrong.

To lighten the chaos here will be given another picture of the difference between the most common Subtractive and the well known, but not much practiced Additive Synthesis:

One can take Subtractive Synthesis as the ”sculptor’s method”, because the sculptor takes something “ready” and refines it by means of tools. The S.S. does it, too. A sample will be processed by some FX-tools.
In both cases something real is going to be changed, e.g. the stone by the hands of the master, the sound through the tools of an skilled musician/engineer.

On the other side, Additive Synthesis is a “painter’s method.
The tiniest element of sound, the sine wave, will be combined with selfsame parts using mathematical and/or physickal algorithms reaching thus a complex sound.
So one comes from simple to complicated, as a painter adds colours to a picture.