Third-Party Cookies
Third-party cookies are small pieces of data stored by websites from domains other than the one the user is currently visiting, typically used for cross-site tracking, advertising, and analytics. They are created when a website includes content from external sources like ads, social media widgets, or analytics scripts. This technology enables user behavior tracking across multiple sites to build profiles for targeted advertising and personalization.
Developers should understand third-party cookies when building web applications that integrate external services like advertising networks, analytics tools, or social media plugins, as they affect user privacy, data collection, and compliance with regulations like GDPR and CCPA. Knowledge is crucial for implementing cookie consent mechanisms, configuring cross-domain tracking, and adapting to browser restrictions like Chrome's phase-out of third-party cookies by 2024. Use cases include ad targeting, A/B testing, and user authentication across affiliated sites.