Django admin template: what is base_site.html

I am currently customizing the admin templates and this makes me wonders that what is the usage/purpose of base_site.html?

I understand that base_site.html extends from base.html but from the original code itself, it only adds HTML content for branding and title blocks. Hence, if I'm overriding the whole base.html, I can just add HTML content for branding and title blocks in base.html and empty the base_site.html.

Please correct me if I am wrong. Thank you