The entry widget provides a single line of text for use as a data entry field. The string in the entry can be linked to a Tcl variable.
Entry widgets are specialized text widgets that display a single line of editable text. They have a subset of the functionality of the general-purpose text widget described in Chapter 33. The entry is commonly used in dialog boxes when values need to be filled in, or as a simple command entry widget. A very useful feature of the entry is the ability to link it to a Tcl variable. The entry displays that variable's value, and editing the contents of the entry changes the Tcl variable.