title: What is the purpose of data modeling cardinality?
body: <p>I understand what cardinality is, so please don't explain that ;-)</p>
  
  <p>I would like to know, what the purpose of doing cardinality is in data modeling, and why i should care.</p>
  
  <p>Example: In an ER model you make relations and ad the cardinality to the relations.
  When am i going to use the cardinality further in the development process? Why should i care about the cardinality?</p>
  
  <p><strong>How, when and where do i use the cardinalities after i finish an ER model for example.</strong></p>
  
  <p>Thanks :-)</p>