Each slot holds a reference to an Object.
class Entry
{
  String name;
  String number;
  // constructor
  Entry( String n, String num )
  {
    name = n; number = num;
  }
  // various methods
  . . .
}
 
Vectors are especially convenient when you want
to maintain a list of your own object types.
Since all classes,
even those of your own invention,
descend from the Object class,
a Vector can be used with  objects of any type.
For example say that you wanted an application that maintained
a phone book.
Each entry in the phone book will contain
a name and a number,
along with various methods.