difference between page template and post format

A page template is a file of PHP.
A post format is an internal WP taxonomy.

is the output different?

That question doesn’t make sense.
There is no “book” post format in the internal taxonomy.
You could write a page template called “book”, and the user can assign it to a page.

Typically, a “book” would be a custom post type, which you define in a plugin. How it is rendered depends on whether your plugin adds a filter for 'template_include' to use its own template, or if you put a template named for the post type in your child theme. See the Template Hierarchy for details.

got it, thanks for explaining

[wrong thread]

• This reply was modified 3 years, 9 months ago by Fawzi.