What is the purpose of a captive portal on a public Wi-Fi network?

• A. To monitor device temperatures.
• B. To require users to sign in or accept terms before access.
• C. To block all access permanently.
• D. To store user passwords

Answer: (B)

A captive portal is a login or terms-acceptance page that appears on public Wi‑Fi before you can use the network. When you connect, the network redirects your first attempts to browse to this page, so you must sign in or agree to terms of use, privacy policy, or acceptable-use guidelines before access is allowed.

This setup gives the network operator control over who can use the service and under what rules, helps enforce usage policies, and often provides a way to present legal notices or collect basic analytics or payment if needed. The other options don’t fit this purpose: monitoring device temperatures isn’t about controlling network access, permanently blocking access defeats the goal of offering a usable public service, and storing passwords isn’t the intended function—authentication may occur as part of the sign-in process, but the portal’s primary purpose is to grant access after acceptance or authentication.