What is backend? Whats the difference between backend and frontend?

It’s Nike's visible (front) and invisible (back) end of the Nike and SNKRS app.

So everything you can see loaded on the nike website and that you can add to the cart is loaded in the frontend, while everything that you can't see but that we can see through the monitors (for example #backend eu) is loaded in the backend. Thanks to this monitor we are able to see when nike uploads some pairs on the site without showing them to everyone and therefore we are able to understand a lot of information such as: when the pairs will be released, if they upload special events such as hunts, exclusive accesses and so on. All pairs currently loaded in backend could be added to favourites anytime.