GUI programming in C

hi
i am BCA student,now i am learning c programming language.Mostly i have done c programming language.I also making some project on base c programming language.But during study i do not understand what is GUI. how is useful for programming language . Is that useful for event action,please any one tell me about that .

Most of traditional style programming ,there are some step wise formulation like step A , after that step B than step C.But now like when user could ask any one of a number of function to be performed in any type of order,any sequential format.You might for some instance,if you want a new file or a click on a button or enter new text.Whole are process done by general user interface.Specially GUI use as random request.A GUI environment handle the random user request by introducing an "event loop".Event loop is a stack various input instruction the user provide like keystroke,mouse click function,set handling function like event or action.means whenever program is run that time handling function are set up and after that loop is started,it continuously on running process until "quit" event is processed.GTK+ is totally written in C

Menu bar,button,text boxes are the various element which can show the important of GUI.Each of them has various function assigned to it,GUI programming work like as a object oriented.One would except an object oriented programming language would be the most useful for developing such application.In GUI use for event -handling function.GTK+ has been designed for use with c.GTK+ is totally written in C .GTK+ itself may considered written in an object oriented manner.object oriented programming language can help to GUI for organize the application.GUI programming has its own set of programming language term.There are some common term available like window which an area of the screen,which controlled by an application.Control which is controlling the application.

GUI application are nearly behave like event driven programming by nature.GUI has its some own programming term such a window,control,widget,frame,layout and child.Most important thing which is GUI programming is a idea of a containment hierarchy.Widgets are the contained of a tree like structure with the top level widget control the entire interface.Basically GUI toolkit based on c programming language only.GTK+ interface is totally written in c.GTK+ is a totally follows an object oriented design program, as well as it is totally open source.