Vegan and gluten-free diets do not mean the same thing. Gluten is a protein found in wheat, rye and barley, meaning that the foods made using them will contain gluten. All vegan diets are not necessarily gluten-free but you have options in vegan foods that are completely gluten-free.
 
Fruits, vegetables, legumes, nuts and many cereals are naturally gluten free. Hence vegans who prefer gluten-free foods can have them. Gluten-free food is trending among fitness conscious people but some choose to avoid gluten-containing foods because they have gluten intolerances or Celiac disease, and may suffer serious side effects from gluten consumption.
 
Foods being gluten-free do not mean they are vegan. Similarly, all vegan foods need not be gluten-free. There are many foods that are both vegan and gluten-free.