Explain why a genetic fingerprint is unique to every individual

The genetic fingerprint is differentiated based on the differing lengths of short tandem repeats (STRs) between genes. Everyone has different lengths of STRs so when their DNA is hydrolysed by restriction enzymes and put on electrophoresis gel, the fragments will be different lengths so travel at different speeds through the gel. So everyone has an individual pattern of DNA bands on the electrophoresis gel. Our STRs are inherited from our parents so our genetic fingerprint will be similar to our parents but never identical.