Question

Is a component that provides a button control in a gui application or applet?

Answer 1

GUI is a graphical user interface. It is a graphical window that provides interaction with the user. 
The button is a pushbutton, which can be pressed to trigger an action.
A graphic control component or a control element is a component that provides a button control in a GUI application. It is also called a control element because it is an element of interaction between the user controlling the application.