title: Denormalization of data in MongoDB
body: <p>I am learning MongoDB and I have a question regarding duplication of data. In the SQL world you try to normalize the data. For instance I have a table with categories and another one with products. Each product may belong to many categories so there is a join between these tables.</p>
  
  <p>However am I right that in MongoDB you don't think like this? Does instead each product have a embedded document(s) of categories? Is that just the way it is? You don't care if the data is duplicated?</p>