Final answer:
Cookies are small pieces of software that track a viewer's activity on a web page. They store information about a user's preferences and browsing behavior, allowing for personalized experiences and targeted advertisements.
Step-by-step explanation:
Cookies are small pieces of software that run on a Web page and are able to track what a viewer is doing on the page. They are commonly used to store information about a user's preferences, login status, and browsing behavior. These cookies can then be used to personalize the user's experience and serve targeted advertisements. For example, a website may use data from past viewing habits gathered through cookies to make predictions about the user's future viewing behavior.