This is for people who can already write small Python scripts and now need code that other people can install, read, test and trust. You will set up projects that don't fight each other, split code into modules and classes, work with real files and CSV data, and prove your code works before someone else finds the bug. If your code only runs on your laptop and only you understand it, it is not finished yet.
This is for people who can already make a page react with JavaScript and now need code that survives real projects: Node and npm, modules, classes, real data, waiting for APIs, and tests. You will set up projects that install the same way on every machine, split code into files other people can read, handle JSON and dates without losing data or a day, and prove your code works before a customer finds out it doesn't. If you skip this level, your code works on your machine with your sample data, and breaks the first time the data changes.