The path is an identifier for a page in the page system.
It represents the fully qualified path in a wiki form (ie the path separator is a : colon)
You can't set a path, the path is protected page metadata.
It can be seen in:
This metadata is known as pagename for Dokuwiki.
A path can be used as variable:
You can create links for instance:
The path of this page is ''$path'' and you can use it in a link: [[$path|link to this page]]
The path of this page is :docs:page:system:path and you can use it in a link: link to this page
You can also use it in a theme template as variable.
{{ path }}
By default, this is the value that is reported in a third analytics tool such as Google Analytics but you can use the permanent canonical path instead.