%} renders the django CMS toolbar.
{% placeholder "content" %} defines a placeholder, where plugins can be
inserted. A template needs at least one {% placeholder %} template tag to be
useful for django django CMS. The name of the placeholder is simply a descriptive
one, for your reference.
Django needs to be know where to look for its templates, so add templates to the
TEMPLATES['DIRS'] list:
Note
The way %}
{% render_block "css" %}
{% cms_toolbar %}
{% placeholder "content" %}
{% render_block "js" %}