Peaks in the functional group region are characteristic of specific kinds of bonds, and therefore can be used to identify whether a specific functional group is present.
Peaks in the fingerprint region arise from complex deformations of the molecule. They may be characteristic of molecular symmetry, or combination bands arising from multiple bonds deforming simultaneously.
The Fingerprint Region 1500-400 cm-1
The Functional Group Region 4000-1500 cm-1