In Tcl/Tk there are currently 15 types of widget.
In alphabetical order they are
(see also library('tcltk/examples/widgets.tcl')):
buttona simple press button
canvasis a container for displaying “drawn” objects such as lines, circles, and polygons.
checkbuttona button that hold a state of either on or off
entrya text entry field
framea widget that is a container for other widgets
labela simple label
listboxa box containing a list of options
menua widget for creating menu bars
menubuttona button, which when pressed offers a selection of choices
messagea multi-line text display widget
radiobuttona button used to form groups of mutually interacting buttons (When one button is pressed down, the others pop up.)
scaleis like a slider on a music console. It consists of a trough scale and a slider. Moving the slider to a position on the scale sets the overall value of the widget to that value.
scollbarused to add scrollbars to windows or canvases. The scrollbar has a slider, which when moved changes the value of the slider widget.
texta sophisticated multi-line text widget that can also display other widgets such as buttons
toplevelfor creating new standalone toplevel windows. (These windows are containers for other widgets. They are not terminal windows.)