What does the term "cookie" refer to in web development?

The term "cookie" in web development specifically refers to a small piece of data that is stored on the user's device by the web browser. Cookies are essential for managing session data that retains user preferences, tracking user behavior, and maintaining the state of user interactions with a web application. For example, when a user logs into a website, a cookie can be created to store their login session, allowing the user to browse the site without needing to sign in again on each page.

Cookies can hold various types of information, such as user IDs, authentication tokens, or other personalized data. They have expiration dates, which can be set by the website, determining how long the cookie remains on the user's device. This functionality is crucial for enhancing the user experience by remembering choices and sessions across multiple visits.

In the context of the other options, while databases are used for storage, they differ fundamentally from cookies as they typically require a server interaction for data reading and writing. Graphical representations are more aligned with elements like images or charts rather than data storage. Caching on the server involves storing copies of files or data to improve load times, which is different from the purpose and functionality of cookies.