isSelected()   -> verifies if the web element is selected or not
               is used with radio buttons, dropdowns and checkboxes.

isDispalyed() -> verifies the presence of a web element within the web page. 
                    If found -> true,   If not found ->  false    
              checks for the presence of all kinds of web elements available
isEnabled()    -> verify if the web element is enabled or disabled within 
                  the web page.
               isEnabled primarily used with buttons