A graphical user interface (GUI) is a visual way to use software with windows, icons, menus, buttons, and a pointer instead of typed commands. In cyber security, GUIs matter because they shape what users notice, trust, and approve. A clear interface can reduce mistakes, but a convincing one can also hide risk or make dangerous actions feel routine.
Attackers often abuse GUIs by building fake login screens, deceptive pop-up dialogs, or malicious installers that mimic legitimate software. They may use clickjacking to trick users into selecting actions they did not intend, or hijack remote desktop sessions to make a system look normal while it is being controlled. Defenders use GUIs for security prompts, permission dialogs, and admin consoles, but those same prompts must be designed carefully so users do not click through warnings without reading them.