Using Django’s Built-in Form Widgets

The same CharField can appear on the page as a one-line text box or as a large text area, and its validation does not change at all. That is possible because a Django form field splits its work with a second object. The field decides which values are valid and converts them to Python. The second object, called a widget, decides how the field looks in HTML and how its value is read back out of the submitted data.

Every field has a default widget, which is why the comment form rendered without you choosing any