A widget toolkit, widget library, GUI toolkit, or UX library is a library or a collection of libraries containing a set of graphical control elements (called widgets) used to construct the graphical user interface of programs.

Toolkit for building graphical interfaces.

A software widget is a relatively simple and easy-to-use software application or component made for one or more different software platforms.

A web widget is a web page or web application that is embedded as an element of a host web page but which is substantially independent of the host page, having limited or no interaction with the host.

A graphical widget (also graphical control element or control) in a graphical user interface is an element of interaction, such as a button or a scroll bar.