What is Cookies?

In plain English

A cookie is a tiny note a website leaves on your computer or phone so it can remember you next time. Think of it like the friendly cafe where the staff remember your usual order — you don't have to explain yourself every visit. When you tick "keep me logged in" or your shopping basket still has items in it an hour later, that's cookies quietly doing their job in the background.

They're just small text files saved by your web browser (Edge, Chrome or whatever you use on Windows or Android). They are not programs, they can't think, and on their own they are not a virus. Some remember helpful things like your login or your preferred language; others ("tracking" cookies) follow what you look at across different sites so advertisers can show you ads — which is why that garden chair you glanced at keeps popping up everywhere.

Why it matters

Cookies are the reason you keep seeing those "Accept cookies" pop-ups on nearly every website — UK and EU privacy rules mean sites have to ask before using the non-essential, tracking kind. For a home user it's mostly about privacy and a tidier web. For a small business with its own website, it matters more: if your site sets tracking cookies, you're legally expected to ask visitors first and explain it, so it's worth knowing it's there rather than being caught out.

What to do

• Don't panic about the pop-ups. "Reject" or "Only necessary" is a perfectly safe choice and the site will still work — you're just declining the tracking, not breaking anything.
• Clearing cookies is a handy fix. If a site is misbehaving or won't log you in, clearing cookies in your browser settings often sorts it. The trade-off: you'll be signed out and have to log back in afterwards, so have your passwords to hand.
• On a shared or public computer, log out properly rather than just closing the tab — that clears the cookie that keeps you signed in.
• Running a business website? Make sure it has a proper cookie banner and a privacy notice. The ICO (the UK's data watchdog) publishes plain guidance, and we're happy to point you in the right direction.

How 365 Techies can help

If a website keeps logging you out, the pop-ups are driving you mad, or you want a hand getting a cookie banner right on your own site, we're a friendly local Dorset team who'll talk you through it without the jargon.

Related: Web browser · Cache · IP address · Malware — or browse the full A–Z jargon buster.