title: What is the use of cleaned_data in Django
body: <p>Django says if <code>form.is_valid()</code> is <code>True</code>.  <code>form.cleaned_data</code> is where all validated fields are stored. But I am confused about using the <code>cleaned_data</code> function.</p>
  
  <p><code>form.cleaned_data['f1']</code> -- cleaned data
  <code>request.POST.get('f1')</code> -- un-validated data</p>
  
  <p>I have a model form in Django. </p>
  
  <pre><code>if form1.is_valid():
      form1.save()
  </code></pre>
  
  <p>Does this save cleaned_data to the model or does it save unvalidated data.</p>
  
  <pre><code>form2=form1.save(commit=False);
  </code></pre>
  
  <p>Does form2 contain form1's cleaned_data or unvalidated data.</p>
  
  <p>Apart from converting any date to python datetime object, is there a good example of benefit of using cleaned_data vs unvalidated data.
  Thanks</p>