CORS explained

CORS needs to know both frontend and backend.
If you don't know this, you may waste time debugging later!

I am a working web developer who has been developing at a startup for 4 years.

I've been mainly working on creating apps from start.
I went through a lot of trial and error.
I want to share what I have learned.

Making the length of the video less than 2 minutes is to compress the information. Time is precious to developers!