Why we use cookies
Two reasons, both practical: so the site works while you are using it, and so we can tell whether the guides are doing their job.
Strictly necessary cookies hold the site together between clicks. Without them, a form page cannot remember that you started typing, and navigation through a long article behaves unpredictably.
Measurement data informs editorial decisions: which topics are read through, where readers leave a page early because a section was unclear, and which guides need an extra example or a clearer chart of daily portions. It is the same kind of signal a kitchen uses when it notices a tray always comes back half-finished.