The basic unsigned integer type System unit
  type Cardinal = 0..4294967295; // At the time of writing
The Cardinal type is an Integer whose size is not guaranteed. It is the basic unsigned integer type in Delphi, and currently has the same capacity as the LongWord : 32 bits.
To hold very large integers, use the Int64 type.
Cardinal is most commonly used in parameter passing to C type functions.
Related commands
Byte An integer type supporting values 0 to 255
Int64 A 64 bit sized integer - the largest in Delphi
Integer The basic Integer type
LongInt An Integer whose size is guaranteed to be 32 bits
LongWord A 32 bit unsigned integer
ShortInt An integer type supporting values -128 to 127
SmallInt An Integer type supporting values from -32768 to 32767
Word An integer type supporting values 0 to 65535
Example code : Showing the capacity of Cardinal
  min, max : Cardinal;
  // Set the minimum and maximum values of this data type
  min := Low(Cardinal);
  max := High(Cardinal);
  ShowMessage('Min cardinalvalue = '+IntToStr(min));
  ShowMessage('Max cardinalvalue = '+IntToStr(max));

Show full unit code
   Min cardinal value = 0
   Max cardinal value = 4294967295