What it is
Ethanol contains oxygen, hydrogen and carbon. Conventional production converts sugars or starches into alcohol through fermentation, then uses distillation and dehydration to reach fuel specifications.
In Canada, conventional fuel ethanol is made principally from corn and wheat. Other pathways can use cellulosic or waste-derived feedstocks, but they should not be described as commercial defaults without evidence.
Why it is blended
Ethanol contributes octane and renewable content. The effect of a blend depends on fuel specification, vehicle compatibility, climate and the lifecycle pathway used to produce and deliver it.
What it is not
Ethanol is not biodiesel or renewable diesel. Those are different fuel families with different molecules, feedstocks, equipment and standards. Canola is highly relevant to those diesel-replacement pathways, not the principal feedstock for conventional ethanol.