Persistent cookies are small text files stored on a user's device by a web browser. Unlike session cookies, which are deleted when the browser is closed, persistent cookies remain on the device for a specified period or until manually deleted. They help websites remember user preferences, login information, and other settings for future visits. These cookies enhance user experience by allowing websites to load faster and provide personalized content. However, they can also raise privacy concerns, as they track user behavior over time. Users can manage persistent cookies through their browser settings, choosing to accept, block, or delete them as needed.