[Answer]-What does pre_save and post_save do in django?

You probably skipped the introduction to signals in the docs:

Django includes a “signal dispatcher” which helps allow decoupled
applications get notified when actions occur elsewhere in the
framework. In a nutshell, signals allow certain senders to notify a
set of receivers that some action has taken place.

Let’s say you want to create a slug you have basically two options:

• Override your model’s save() method
• Use the pre_save signal of your model