Why create loops and branches with the variable name in the condition?

Question

Django

The django documentation has this html code:

{% if error_message %}<p><strong>{{ error_message }}</strong></p>{% endif %}

Here, the condition contains the name of the variable, if you remove the condition, the code still works, please tell me what is the meaning of such conditions, which are fulfilled anyway. I also saw something similar with a while loop.

Answer 1

The point is not to load the DOM with empty tags.