Difference tracker and cookies
Executive summary
Trackers is an umbrella term for on‑page technologies—scripts, pixels, cookies and more—used to collect data about a user’s interactions; cookies are one specific, long‑established kind of tracker, typically small text files stored by the browser to remember state or identity (e.g., logins, preferences) [1] [2]. Modern tracking goes beyond cookies (pixels, fingerprinting, “supercookies”) and can be stateful (browser‑stored identifiers) or stateless (device/browser fingerprinting), which has important consequences for privacy and for how browsers and laws attempt to block tracking [3] [4].
1. What “tracker” means — a category, not a single technology
“Tracker” is used by privacy tools and vendors as a general label covering embedded commands, scripts, pixels, and cookies that gather behavioral data on a site or across sites; some trackers are benign (site functionality or analytics) while others are designed for profiling and ad targeting [1] [5]. Startpage, for example, describes trackers as embedded scripts, tracking cookies and pixel tags that derive data points about browsing behavior [6].
2. Cookies in plain terms — small text files with a memory function
Cookies are small pieces of text downloaded to a browser that store state — session cookies expire when the browser closes, persistent cookies stay until they expire — and are commonly used to remember logins, shopping carts and site settings [2] [7]. That memory role is why cookies are often essential for site functionality even though the same mechanism can be repurposed for cross‑site tracking [7].
3. Tracking cookies and third‑party cookies — when cookies become surveillance tools
A “tracking cookie” or third‑party marketing cookie is set by domains other than the site being visited and is used to follow activity across multiple sites to build profiles for advertising or measurement; these are the cookies most associated with privacy concerns [8] [9]. Some coverage frames tracking cookies as “specialized” cookies that record and report browsing entries back to their designers, highlighting why users and regulators focus on them [10].
4. Other trackers — pixels, scripts, fingerprinting and “supercookies”
Tracking pixels (tiny, often invisible images or network requests) and embedded scripts can measure conversions and ad effectiveness without storing a browser file; fingerprinting techniques create identifiers from browser and device characteristics rather than saved cookies, making them harder to block [9] [4] [3]. The industry distinguishes stateful techniques (cookies, supercookies) that store an identifier locally from stateless fingerprinting that derives an ID from system attributes [3].
5. How blocking and regulation treat the difference
Browser and extension approaches vary: many tools block third‑party trackers or cookies by default while allowing essential third‑party resources to function; Startpage’s extension, for instance, blocks third‑party trackers by default and may selectively block cookies for known essential resources rather than full blocking [6]. European privacy rules explicitly treat a range of “trackers and similar technologies” together, requiring user information and often opt‑in consent for both cookies and pixels, which underlines the regulatory view that cookies are one of several tracker types [4].
6. Practical takeaway — what to expect and the limits of control
Users can delete or block cookies fairly easily in most browsers and opt out of some tracker categories, but blocking cookies doesn’t eliminate stateless fingerprinting or more persistent “supercookie” techniques; anti‑tracking tools try to replace or randomize identifiers to frustrate tracking, but the tracking ecosystem adapts [2] [3]. Reporting and vendor docs agree: cookies are the best‑known tracker and remain useful for website functionality, but privacy risk depends on who sets the cookie (first vs third party) and what other tracker technologies are in play [7] [8].