How are cookies involved in web sessions?

• A. Cookies store the entire session state on the server.
• B. Cookies can store session identifiers so the site can remember you as you navigate pages.
• C. Cookies terminate a session when the browser closes.
• D. Cookies encrypt the session data.

Answer: (B)

Cookies help maintain continuity of a web session by storing a small piece of information—the session identifier—on your browser. When a session starts, the server creates data about you (like who you are or what you have in a cart) and sends back a cookie that contains a session ID. As you move from page to page, your browser sends that cookie with each request, and the server uses the ID to fetch the correct session data. This lets the site remember you without sending all your information every time.

Storing the entire session data in a cookie would mean sending a lot of data with every request and raises security and size concerns, which is why the server keeps the real session data and the cookie only carries the ID. Terminating a session when the browser closes isn’t guaranteed—some cookies are designed to persist, while others disappear on close—so it isn’t a reliable description of how sessions are managed overall. Cookies don’t inherently encrypt the session data; encryption can be used as an extra protection layer, but it isn’t what cookies themselves do.