What is Combo Boxes?
Combination of text entry field and dropdown list that allows users to choose from existing options or type in an entirely new entry. A combo box is a GUI feature that combines a drop-down box, list box, and an editable text field that gives the user several ways to input or select the desired information.
Combo Box is a graphical user interface widget. Traditionally, it is a combination of a list box and a single-line editable textbox, which allows the user to either type a value directly or select a value from the dropdown list.
Combo box refers specifically to a drop-down list, which allows only selected options to choose and the user cannot type a value and if the selection field has edit control, the user can enter additional information manually.