a short integer variable that "indicates" the value or condition of its host variable
                                                            
                                                     
                        
                                                
                        
                        
                            a variable that takes on a finite number of values, such that each value represents a different category of a nominal variable
                                                            
                                                     
                        
                                                
                        
                        
                            binary variable that is coded with the values 0 and 1. A 1 represents the presence of some characteristic, whereas 0 represents its absence.