Template inheritance is a way to define base template structure and reuse it in multiple places. The parent templates define areas for the child templates to overwrite with the "block" keyword. The child inherits this template with the "extends" keyword.
Example: if we have the parent template base.jade:
// base.jade h1 Hello from the base block content
And we want our child to use it:
// child.jade extends base block content p This is the child's content
This will output:
<h1>Hello from the base</h1> <p>This is the child's content</p>
Templates can have many blocks and inherit multiple levels.