No two people share the same fingerprint. Identical twins do not even have the same fingerprints, even though they share the same genetic DNA.
Fingerprints begin developing when ridges are formed on the outermost layer of skin, on your fingertips. The ridges form a pattern that is your unique fingerprint.
These ridges are developed during weeks 20 to 24 of gestation and will not changes as a person ages. Your fingerprint will change in size but the patterns the ridges that are formed will remain the same from infancy to adulthood.
The unique identifiers come from the varying number, and spacing of the ridges, even though everyone can be classified into three categories or patterns.
Wondering what category or pattern you fit into?