DNA stands for deoxyribonucleic acid. It is the hereditary material found in all known living organisms and many viruses. DNA carries genetic information necessary for the growth, development, functioning, and reproduction of organisms. Structurally, DNA consists of two long strands forming a double helix, with sequences of nucleotides that encode genetic information. Each nucleotide comprises a sugar, a phosphate group, and a nitrogenous base, which can be adenine, thymine, cytosine, or guanine. The study of DNA has revolutionized fields such as genetics, forensic science, and medicine, leading to advancements in understanding heredity, evolution, and biotechnology.