You shape your life in a way that eliminates every item of animal origin. You consume anything that’s free of animal products: no meat, milk, eggs, wool, leather, honey and so forth. Your sandwich, your shampoo, and even your shoes or your mattress fit into that category.
You may be vegan for one of the following reasons:
avoidance of animal mistreatment and slaughter
elimination of certain health risks
reduction of environmental footprint
Whatever motivates you, being vegan drives all of your purchasing decisions.