What are cookies?

A cookie is just a small text file a website stores in your browser so it can remember something about you between page loads or visits. That is the whole idea. Everything else is detail.

What a cookie actually holds

A cookie is a tiny piece of text, usually a name and a value, that a site asks your browser to keep. The next time you visit, the browser hands that text back so the site can recognise the session. It is not a program, it cannot run, and it cannot read files on your computer. It simply remembers a value, such as "logged in", "cart has 2 items", or a random ID that stands in for you.

First-party vs third-party cookies

A first-party cookie is set by the site you are actually on, and it powers the useful stuff: staying logged in, keeping a basket, remembering your language. A third-party cookie is set by a different domain embedded in the page, such as an ad network, and it is the kind used to follow you across sites. Browsers are phasing third-party cookies out, which is exactly why tracking has got harder.

What cookies are used for

• Essential: logins, baskets, security. The site breaks without them.
• Analytics: counting visits and conversions, usually through GA4.
• Marketing: remembering you for retargeting ads and measuring which ad drove a sale.

Why every website asks now

Laws such as GDPR and PECR say that non-essential cookies, the analytics and marketing kind, need your consent before they are set. That is why you see a cookie banner on nearly every site. We cover the why in more depth in why every website asks about cookies.

Datahound are analytics and ad-tracking specialists. We fix broken GA4, Google Tag Manager and server-side tracking so every sale, form and call gets counted. Back to datahound.agency · All tracking guides · Should I accept cookies?