title: Has and belongs to many implementation Questions / Tags
body: <p>Lets take Stackoverflow as an example:</p>
  
  <p>Two models: Questions and Tags</p>
  
  <p>A Question can have many Tags.</p>
  
  <p>Should a separate table "Question_tags" be created to manage the associations or is there a way to create an array field in the Questions table.</p>
  
  <p>Which is better? Would a dedicated "Question_tags" table be overkill?</p>