Hi Rbassie, first of all NO question is silly. A dado blade is a set of blades place together on a table saw, it is used for making wide cuts on wood. For example, if you're making a bookcase you'd want to use the dado blade to make cuts in the sides for shelves to fit into. Here's an interesting link to a woodworking dictionary that you might be interested in, it's http://www.samallen.com/dictionary.html

Thanks a lot