A checkbox is a graphical widget that allows the user to make a binary choice, i.e. a choice between one of two possible mutually exclusive options. For example, the user may have to answer 'yes' or 'no' on a simple yes/no question.
Checkboxes are shown as empty boxes when unchecked, and with a tick or cross inside when checked. A caption describing the meaning of the checkbox is normally shown adjacent to the checkbox. From Wikipedia
