Two people cannot have the same DNA, as even identical twins do not have identical DNA. DNA stands for deoxyribonucleic acid. It is the biological instruction that makes each species unique.
DNA was discovered by the Swiss biochemist Frederich Miescher in the late 1800s, though it took almost another century for researchers to learn of its importance to biology. DNA is found inside the nucleus of each cell. DNA is made up of nucleotides, which are made up of three parts: a sugar group, a phosphate group and one of four types of nitrogen bases. Human DNA contains 3 billion bases and around 20,000 genes on 23 pairs of chromosomes.