VARCHAR2 is variable length character datatype while CHAR is fixed length datatype.

If you have column defined as VARCHAR2(10) and you want to store value 'Hi' in there, Oracle will store only those two characters in that column. If on the other hand the column is of type CHAR10), then everything you store in there is right blank-padded to the length of 10. So the value 'Hi' will actualy be stored as those two characters plus 8 blank characters.

http://download-west.oracle.com/docs...datyp.htm#7223