What is in a fingerprint?
A fingerprint is the mark that the ridges of your finger leave when applied to a surface. The easiest way to record your fingerprint is by applying ink to your finger and then pressing it firmly onto a paper surface. Many records of fingerprints now, however, are electronic, copying your fingerprint into a database for matching. People can also "dust" for fingerprints because of the oil on our hands. The oil will deposit in the shape of the ridges, and the dust will cling to the oil revealing the fingerprint.
Fingerprints are used primarily for identification, because many experts agree that every person has a unique ridge pattern on the tips of their fingers. Thus, fingerprints are taken for security clearance, background checks and prison visits, and collected at crime scenes.
Fingerprints can also be used in lieu of keys or codes for gaining access to private areas.