Boolean isSelected(): This method determines if an element is selected or not. It returns true if the element is selected and false if it is not. It is widely used on check boxes, radio buttons and options in a select.
Boolean isDisplayed(): This method determines if an element is displayed or not. It returns true if the element is displayed and false if it is not. Advantage of this method is that it avoids parsing an elements style attribute.
Boolean isEnabled(): This method determines if an element is enabled or not. It returns true if element is enabled (All elements apart from disabled input elements) and false if otherwise.