Strapi is a self-hosted, fully-customizable, headless CMS that uses Javascript in its operations. Hooks are one of the main built-in developer interfaces that we can use to customize and extend Strapi's default functionality.
This is a companion discussion topic for the original entry at https://strapi.io/blog/understanding-the-different-types-categories-of-strapi-hooks
This article says it has been updated for Strapi v4 but it needs checking again. The section about local hooks does not work; hook.js appears to do nothing in v4. I’ve been trying to figure out the right approach and I think you’ve got to make a plugin instead. Unfortunately this article is the top Google result for anything related to Strapi hooks and it’s really hard to know which parts are accurate.