The text box may be used to enter one (variable) text, with the possibility of offering one initial (default) value.
The list box may be used to select one value from a pre-established list. A number of selections from this list will always be displayed, possibly with a scroll-bar to indicate that there are more possible selections that are not currently visible.
The drop down list box may be used to select one value from a pre-established list. Normally, only the current selection will be visible. While selecting, a number of selections from this list will be displayed, possibly with a scroll-bar to indicate that there are more possible selections that are not currently visible.
The combo box may be used to select one value from a pre-established list, or enter a different value. A number of selections from this list will always be displayed, possibly with a scroll-bar to indicate that there are more possible selections that are not currently visible.
The drop combo box may be used to select one value from a pre-established list, or enter a different value. Normally, only the current selection will be visible. While selecting, a number of selections from this list will be displayed, possibly with a scroll-bar to indicate that there are more possible selections that are not currently visible.
The long list box may be used to select one or more values from a pre-established list. A number of selections from this list will always be displayed, with a scroll-bar to indicate that there are more possible selections that are not currently visible.
(A long list box will only show all its control buttons when it has enough space to display them all.)