Usually total war is used to describe the complete society of a country going to war: military, economy, and culture/etc.
Only in revisionist history.
In reality, total war is when you wipe out *everything* associated with your enemy. That includes women, children, the elderly, whoever is in the way or offers resistance to your troops.
The idea is to inflict such horrors on the enemy that they give up rather than watch the things they hold dear be destroyed.
It's not a new idea either. There's examples throughout recorded history. The interesting thing is that it usually *works*, if you inflict the proper amount of devastation.