Add to ChromeA
Ad Blocker
A browser extension or app that prevents advertisements from being downloaded or displayed.
Advertising ID
A resettable per-device identifier iOS and Android give to apps for ad tracking.
App Tracking Transparency
The iOS prompt that requires apps to ask permission before tracking you across other apps and sites.
B
C
CCPA
California's data-privacy law giving residents rights over how businesses collect and sell their data.
CNAME Cloaking
A technique where a site disguises third-party tracking requests as first-party using DNS aliases.
Container Tab
A browser feature that isolates cookies and storage between tabs so different identities don't mix.
Content Blocker
Apple's name for the sandboxed extension API on iOS Safari that returns blocking rules.
Content Security Policy
A header that limits which scripts, styles and other resources a page is allowed to load.
Cookie
A small piece of data a website stores in your browser to remember state between requests.
Cookie Consent Banner
The pop-up asking permission to set cookies, required in jurisdictions like the EU and UK.
Cross-Origin (CORS)
The browser rule that stops scripts on one site from reading data from another site without permission.
Cross-Site Request Forgery
Tricking a logged-in user's browser into sending an unwanted authenticated request to another site.
Cross-Site Scripting
A vulnerability that lets an attacker run JavaScript in another user's browser session on a trusted site.
D
Dark Pattern
A user-interface choice that tricks people into doing something they didn't intend.
Data Broker
A company that buys, aggregates and resells personal data about individuals.
declarativeNetRequest
The Manifest V3 API that lets extensions block or modify network requests using pre-declared rules.
DNS
The internet's phone book: it translates human-readable domain names into IP addresses.
DNS over HTTPS
A protocol that encrypts DNS queries inside HTTPS so they can't be read or modified in transit.
F
Fediverse
A network of interconnected social platforms (Mastodon, Pixelfed, Bluesky-ATProto) built on open protocols.
Filter List
A regularly-updated list of URL patterns and CSS selectors used by ad blockers to decide what to block.
FLoC / FedCM / Privacy Sandbox
Google's umbrella project of replacement APIs meant to enable advertising without third-party cookies.
H
HSTS
A header that tells browsers to only ever load a site over HTTPS, even if the user types http://.
HTTP/3
The latest version of HTTP, built on QUIC over UDP, designed for lower latency and better mobile behaviour.
HTTPS
The encrypted version of HTTP, the protocol your browser uses to talk to websites.
HTTPS-Only Mode
A browser setting that upgrades all requests to HTTPS and warns when only HTTP is available.
M
Malvertising
The use of legitimate online advertising networks to deliver malicious code or scams to users.
Man-in-the-Middle Attack
An attacker positioned between you and the site you're talking to, reading or altering traffic.
Manifest V3
The current Chrome extension platform, which replaces the webRequest blocking API with declarativeNetRequest.
P
Passkey
A phishing-resistant replacement for passwords built on public-key cryptography.
Password Manager
An app that generates, stores and autofills unique strong passwords for every site.
Phishing
An attempt to trick users into handing over credentials or money by impersonating a trusted entity.
Prefetch / Preload
A browser optimisation that fetches likely-next resources before you actually request them.
Private / Incognito Mode
A browsing session that doesn't save history, cookies or form data locally when you close it.
R
S
Safe Browsing
A browser service that warns before you visit a known phishing or malware site.
SameSite Cookies
A cookie attribute that controls whether the cookie is sent on cross-site requests.
Server-Side Tagging
Sending analytics and ad events from a first-party server instead of directly from the browser.
Service Worker
A background script that lets a site intercept network requests, cache responses and work offline.
Session Cookie
A cookie that lasts only until you close the browser, used to keep you signed in within a single visit.
SNI / Encrypted Client Hello
The field in a TLS handshake that reveals which hostname you're visiting — and the effort to encrypt it.
Storage Partitioning
Keeping cookies, cache and storage separated per top-level site so trackers can't correlate across the web.
Supercookie
A tracking identifier stored in a place that survives normal cookie deletion.
T
Third-Party Cookie
A cookie set by a domain other than the one in the address bar, used to track users across sites.
TLS
The cryptographic protocol that secures HTTPS and most modern network traffic.
Topics API
Chrome's replacement for third-party cookies that lets sites read a short list of your recent interest categories.
Tor
A network that anonymises traffic by bouncing it through three encrypted relays run by volunteers.
Tracker
Code, pixel or request that collects information about a user across websites.
Tracking Pixel
An invisible image used to silently report a page view or event back to a tracker.
Two-Factor Authentication
Requiring a second credential — a code, a hardware key, a passkey — in addition to a password.