Sphinx uses the Jinja templating engine for its HTML templates. Jinja is a text-based engine, and inspired by Django templates, so anyone having used Django will already be familiar with it. It also has excellent documentation for those who need to make themselves familiar with it.
The most important concept in Jinja is :dfn:`template inheritance`, which means that you can overwrite only specific blocks within a template, customizing it while also keeping the changes at a minimum.
Inheritance is done via two directives, extends and block.
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