GUI (Graphical User Interface) is a visual and interactive interface that enables users to interact with and control a software application or a digital device, such as a computer, a mobile phone, or a game console. GUIs typically consist of graphical elements, such as icons, buttons, menus, forms, and windows, and can use various input methods, such as a mouse, a keyboard, or a touch screen. GUIs can provide a user-friendly and intuitive experience, and can enhance the usability, accessibility, and aesthetic appeal of a software application or a digital device. GUIs can be designed and developed using various tools and technologies, such as graphic editors, UI frameworks, or coding languages, and can be tested and optimized to ensure their functionality, compatibility, and performance. GUI design and development can involve various principles and techniques, such as information architecture, usability testing, and visual design, and can play a crucial role in the success of a software application or a digital device.