Jonathan Rueffer
Science Editor
When visiting a website, you have probably encountered a pop-up banner asking you to accept cookies. You have also likely clicked “accept all” or “accept necessary cookies only” just to make the notification disappear. But what are cookies, and what does accepting them actually mean?
Cookies (or internet cookies) are text files with small pieces of data that are used to identify your device as you browse the web. When you visit a website, the server where the website is hosted generates the cookie information and sends it to your website browser, where it is stored locally on your computer. Each time you return to that website, your browser sends the cookie back to the server, allowing the site to recognize you.
Although they are hidden, cookies are an integral part of how the modern internet works. They allow websites to remember information such as login status, language preferences and items placed in a shopping cart. For example, when you remain logged into a site or add items to your cart without checking out immediately, cookies are what make that seamless experience possible.
There are several different types of cookies, each serving a distinct purpose. Session cookies are temporary and are deleted when you close your browser, helping websites track activity during a single visit. For example, necessary cookies are session cookies that are functionally needed to run the requested website,such as remembering your login credentials. In contrast, persistent cookies remain on your device for a predetermined period of time and are used to remember information across multiple visits. Authentication cookies are generated when logging into an account, ensuring that sensitive information is delivered to the correct user. An important category is third-party cookies, which are created by websites other than the one you are currently visiting. These are commonly used for tracking user behavior across multiple websites, often for advertising purposes.
This tracking capability introduces significant privacy concerns. Third-party cookies can build detailed profiles of users by collecting browsing data across different sites, sometimes connecting that information to real-world identities. How much control users have over their personal information online is an ongoing issue.
International privacy laws, like the E.U.’s General Data Protection Regulation (GDPR), and state laws, like the California Consumer Privacy Act (CCPA), address the proper use of cookies, often requiring websites to ask users to provide informed consent as to how their information will be used. This is why cookie banners have become extremely common, as they are designed to give users more transparency and control over how their information is used.
While cookies themselves are not inherently harmful, the way they are used can have significant privacy-related consequences. The cookie banners reflect a broader shift toward data transparency, but also highlight how much of the modern internet relies on the collection of user data.