Topps Tiffany.
The yearly issued base set would be considered the regular issued Topps set. The Tiffany set is a high end set of cards, issued by Topps. These sets were identical to the regular issue...
Card Number.
The card number located on the back is to identify the card in a numbered set. The number is typically located at the top, and appears in a circle. A player might have more than one card...