There is such a big distinction between both. A vegan is someone who does not use meat, seafood, dairy products, egg, and any other item derived from animals. On the other hand, a vegetarian consumes not just plant-based goods, but they may also eat dairy products. Some people even consume certain types of seafood and claim that they are vegetarians.
 
The difference is not concerned with diet alone. A vegan does not even use products including apparels and garments made from the skins of animals. Conversely, vegetarians may use these goods. Think of veganism as a strict form of vegetarianism. There exist different forms of vegan diets, such as raw vegan, dietary vegan and so forth. However, I do not accept the idea of part vegan. You might use only plant-based goods; if you do not do it, you would be no vegan.