Further reading
The Remix documentation outlines the full stack data flow in Remix here: https://remix.run/docs/en/2/discussion/data-flow.
You can find Remix’s documentation about data loading here: https://remix.run/docs/en/2/guides/data-loading.
You can find Remix’s documentation about mutations here: https://remix.run/docs/en/2/guides/data-writes.
The Remix team has created an amazing video series called Remix Singles that goes in depth into how to work with data in Remix. The series starts with a video about data loading, which you can find here: https://www.youtube.com/watch?v=NXqEP_PsPNc.
MDN Web Docs is a great place to learn more about the HTTP protocol: https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP.