Cookies are not only biscuits
A cookie is a small file a page leaves in the browser. It tells it: this visitor has already been here. Some cookies are necessary — without them you would sign in to school over and over. Others serve ads and measuring. Those optional ones you can refuse.
Ads after refusing do not vanish. Part of personalisation vanishes. You will still see a poster. Just less “we know exactly it is you and that you looked at football boots last night”.
In the tracking lesson we talked about the bar on a website. Here we go deeper: what cookies do, how to set them in the browser and what to write into the phone audit.
Three kinds of cookies
Necessary — sign-in, a basket, security. Without them the page does not work. You do not refuse those.
Functional — they remember language, font size. Sometimes yes, sometimes no. It depends on the page.
Advertising / measuring — they track what you click and pass it to ad networks. You refuse those when the bar offers a choice.
If the bar offers only Accept all and More information, go into More information or Settings. There is often Reject optional. It is not rude. It is your trail.
The big Accept all button is big on purpose. The small button is the one you want. If the page breaks after refusing, switch it back on once. Most of the time it does not break.
Settings in the browser
Cookies live mainly in the browser. The phone also has tracking between apps — we dealt with that elsewhere. Now the browser.
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Safari (iPhone): Settings → Safari → switch on Prevent Cross-Site Tracking. In Safari: three lines or the aA icon → Website Settings → Riêng tư.
Chrome (Android/iPhone): three dots → Settings → Riêng tư and security → Block third-party cookies (or Block third-party cookies).
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Open one website that is not a school test. Find the cookie bar. Click Reject optional or Necessary only.
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Write into the phone audit: Safari/Chrome — cross-site tracking off yes/no and one bar — optional refused yes/no.
The browser can also wipe all cookies at once. Do that with a parent. Sign-in to games and school will disappear too. To start, refusing optional on one bar is enough.
What to say at home
To a parent at the computer:
“Look at this button. Accept all is big. We want Necessary only. I can click it on one website and you will see the page still works.”
To a sibling who taps yes from habit:
“Wait. This is not a game. It is a stamp for ads. Click the small one. I watch, you click.”
Into family rules a sentence can go: We refuse optional cookies. Do not touch the school browser blind.
A school Chromebook, a school profile, a test in Moodle — that is not a practice ground. A teacher needs you to sign in and hand in work. A home browser and your own phone yes.
What cookies are not
It is not someone seeing you through a window. It is not a reason to panic. It is a notepad of companies. You do not have to fill that notepad for them.
It is also not a how-to for chasing a classmate. Someone else’s history, “find out where they clicked” — that does not belong here. Shadow watches your trail.
Now you 💪
On one website (not a school test) find the bar and click reject optional. Show a parent that it works.
If there is no bar right now, open Tracking settings in the browser and check cross-site tracking. Write the result into the phone audit.
Check: You can not jump on Accept all. You know the difference necessary vs. advertising. You can find cookie settings in Safari or Chrome.
What to take from this lesson
- Cookies = a trail. Some must be there (sign-in). Some must not (ads).
- Refuse optional. A big button is not a duty.
- Do not touch the school browser blind.
- Write into the phone audit: bar refused, cross-site tracking off.
© 2026 Ing. Martin Polak / AlgoRhino · Điều khoản sử dụng nội dung