Regarding the Plates framework, the render() method of rendering templates

Question

//Original code
public function edit($id='')
{

$row = (new User())->get('user',[' id','name','dept','art','email'],['id'=>$id]);

return $this->view->render( 'admin::index/edit', [
'title' => 'Edit record',
'url' => '/admin/index/save',
'row' => ; $row,
]);
}

This paragraph render('admin::index/edit',...

admin I understand it is the alias defined before, but what does this double colon mean? Why is it not a slash '/'