analytics-dictionary / term / tracking & measurement
Cookie
A cookie is a small file stored in the browser that lets a website remember information about a visitor.
Written by Reflective Data experts · updated Oct 5, 2026
Analytics tools use cookies to recognise returning visitors and to group events into sessions. First-party cookies are set by the site you visit, third-party cookies by other domains.
Privacy laws and browser changes limit cookies, which is why consent management and server-side approaches matter more every year.
related
Consent ModeFirst-party dataThird-party cookies
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