Answer:
Cookies
Step-by-step explanation:
Note that the term, first-party trackers, and third-party trackers are the kinds of Cookies used on sites. However, Cookies are simply files created and stored on a user's web browser when they visit some websites to gain insight into their behavior and preferences.
Thus, we can rightly refer to it as the term that best describes how websites track user data while they are online and browsing content.