I am trying to learn more about the history of vegetarianism, are you vegan by any chance?
I'm vegetarian! The practice of not eating meat has roots in ancient Indian and Greece civilizations. 
OK and it means not eating meat but what about eggs cheese or milk?
Some vegetarians will eat milk and eggs ad even sea animals like fish. 
What about shellfish?
Yes, some vegetarians will eat exoskeleton-bearing aquatic invertebrates like mulluscs and crustaceans. Do you like shellfish?
I do. Can you tell me the difference between Vegan and Vegetarian? Its confusing
Well vegetarians will simply not eat mean, while vegans do not eat any animal products whatsoever. So no milk, eggs, honey etc. Vegans will usually also have ethical reason for not using the products. Vegetarians make up about 0.5% of the population in the Western World.