what are the meanings of cf,of and af flags in eflag？

CF: This flag indicates an overflow condition for unsigned-integer arithmetic.
Set if an arithmetic operation generates a carry or a borrow out of the most-significant bit of the result; cleared otherwise.

OF: This flag indicates an overflow condition for signed-integer (two’s complement) arithmetic.
Set if the integer result is too large a positive number or too small a negative number (excludingthe sign-bit) to fit in the destination operand; cleared otherwise.

AF: This flag is used in binary-coded decimal (BCD) arithmetic.
Set if an arithmetic operation generates a carry
or a borrow out of bit 3 of the result; cleared otherwise.