The difference between wax and shatter begins in the processing steps. They are both extractions, which means that the major oils in the marijuana plant that produces psychedelic effects are extracted and converted into a more concentrated substance. The terpenes, cannabinoids, and flavonoids are collected to create a concentrated product to generate a more drastic high that lasts longer than smoking the plant alone.
Extraction that produces wax will use less heat than one that produces shatter. It will also mix the concentrate much more aggressively for wax than shatter. In wx, the molecules are much more loosely held together in a haphazard fashion. This is the easier product to create. Shatter requires more precision. Instead of the muddle of molecules in wx, the molecules in shatter are tightly aligned. The filtration of shatter is also more meticulous, leading to a more pure product than wx.