A short sequence of DNA encodes multiple characters of an individual which makes us different from one another. Many species possessed different characters imbibed in DNA strand. This book described the DNA sequence which makes us different from one another. DNA barcoding is a new method for the quick identification of any species based on DNA sequence from a tiny tissue sample of any organism. As a biodiversity discovery tool, DNA barcoding helps to flag species that are potentially new to science. DNA barcoding first came to the attention of the scientific community in 2003 when Paul Hebert's research group at the University of Guelph published a paper titled "Biological identifications through DNA barcodes". Since then, DNA sequence is being used to identify different species in the same way a supermarket scanner uses barcode of their products.