These subtle but important differences come into play when you assign, compare, insert, update, select, or fetch character values. So, information about trailing blanks is lost.
Character values are assigned intact, so no information is lost.
Comparing Character Values You can use the relational operators to compare character values for equality or inequality. Comparisons are based on the collating sequence used for the database character set. One character value is greater than another if it follows it in the collating sequence. So, if both values in a comparison have datatype CHAR , blank-padding semantics are used. All string literals have datatype CHAR .