Nachos are a dish that originates from Northern Mexico.  
What are in nachos?
It is a dish with tortilla chips and it is covered in cheese.  It is typically a snack food
What kind of cheese is it covered in?
Mexican cheese, which dates back to the Spanish conquest
That sounds delicious. Where can I get Nachos?
Pretty much any place that service Mexican food.  You can even get more elaborate nacho that have more ingredients. They can be served as the main dish