Parts of this description are "borrowed" from Tcl extension [snit], as the functionality is mostly identical.
public component comp ?-inherit? protected component comp ?-inherit? private component comp ?-inherit?
The component command is used inside an [incr Tcl] extendedclass/widget/widgetadaptor definition to define components.
Explicitly declares a component called comp, and automatically defines the component's instance variable.
If the -inherit option is specified then all unknown methods and options will be delegated to this component. The name -inherit implies that instances of this new type inherit, in a sense, the methods and options of the component. That is, -inherit yes is equivalent to:
component mycomp delegate option * to mycomp delegate method * to mycomp