Cookies are small pieces of data stored on a user's device by websites they visit. They serve various purposes, such as remembering user preferences, improving website functionality, and providing a personalized browsing experience. These text files allow websites to track user activity, analyze site traffic, and customize content to suit individual interests. While they enhance user experience, there are concerns about privacy and data security. Many websites now require user consent for cookie usage, ensuring transparency and giving individuals the option to manage their preferences regarding cookie acceptance and data collection.