title: Instantiated classes vs static classes?
body: <p>I'm struggling to know whether I should use a static or instantiated class.</p>
  <p>I'm not sure I understand why you would use either apart from, a static class should be used to work on data where as a instantiated class has its own data.</p>
  <p>I'm not sure how this apples to my work, for example, I have a model that gets data from a database (a list of products).</p>
  <p>If my above assumption is correct then I should instantiate the model, as the class has it's own data.</p>
  <p>And for example, if I then had a helper class that converted dates, this should be static, as it just returns data in a different format.</p>
  <p>Is all of this correct, can anyone explain to me clearer or any sort of rules I should use when deciding between a static and instantiated class?</p>