DNA stands for deoxyribonucleic acid, which functions as the carrier of hereditary information in all living things. In DNA, a great number of personal traits are encoded, such as a person's sex, eye color and hair color. DNA is located in the chromosomes, of which each human cell (excluding the sex cells) possesses 23 pairs.

If you were to compare the DNA of two random individuals, more than 99% of their genetic data would be identical. However, due to the size of the human genome, there are still more than three million differences between people. These differences account for the great diversity that we perceive in the people around us, and determine the uniqueness of each individual. A person's sex, for example, is encoded in the sex chromosomes (X and Y). Visually, the structure of DNA can be represented by the, now famous, double helix.