A dialog box is a window that appears on a computer screen, typically used to gather information from or provide instructions to the user. It often contains input fields for text, checkboxes, radio buttons, and other interactive elements that allow users to interact with software applications in a more intuitive way than through command-line interfaces or text menus. Dialog boxes are commonly used in graphical user interface (GUI) environments such as Windows, macOS, and Linux operating systems, as well as many types of software programs.