A widget is an element of a graphical user interface (GUI) that displays information or provides a specific way for a user to interact with the operating system or an application.
Widgets include icons, pull-down menus, buttons, selection boxes, progress indicators, on-off checkmarks, scroll bars, windows, window edges (that let you resize the window), toggle buttons, form, and many other devices for displaying information and for inviting, accepting, and responding to user actions.