I'm a vegetarian which means I don't eat meat or any by-products of animals slaughter. 
Uhmnnn! Sure your not missing something?
Nope I don't eat meat out of respect for sentient life. 
What's a sentient life?
Anything that is able to think. Other people are vegans because of their religious beliefts. 
OK ,so how does religion influence veganism
aesthetic, economic, or personal preference. There are variations of the diet as well: an ovo-lacto vegetarian diet includes both eggs and dairy products, an ovo-vegetarian diet includes eggs but not dairy products, and a lacto-vegetarian diet includes dairy products but not eggs. A strict vegetarian diet – referred to as "vegan" – excludes all animal products, including eggs and dairy. Avoidance of animal products may require dietary supplements to prevent deficiencies such as vitamin B12 deficiency, which leads to pernicious anemia.
pass your lips. They told all the meat-eating Kagyupas, “You can’t be a Kagyupa if you eat meat.” I did not say anything that inflammatory. If a Mahayana practitioner, who considers all sentient beings to be like their father or mother, eats the flesh of another being out of carelessness and without any compassion, that is not good. So we need to think about this and pay attention to it. All of us Mahayana practitioners, who accept that all sentient beings have been our mothers