(+) Isomer of glyceraldehyde has ‘D’ configuration It means that when
its structural formula is written on paper following specific conventions
which you will study in higher classes, the –OH group lies on right hand
side in the structure All those compounds which can be chemically
correlated to D (+) isomer of glyceraldehyde are said to have D-
configuration whereas those which can be correlated to ‘L’ (–) isomer of
glyceraldehyde are said to have L—configuration In L (–) isomer –OH
group is on left hand side as you can see in the structure