DNA stands for deoxyribonucleic acid in molecular biology. It is the hereditary material found in almost all living organisms, carrying the genetic information necessary for growth, development, and reproduction. DNA is structured as a double helix composed of nucleotides, which are the building blocks containing a sugar, phosphate group, and a nitrogenous base. These sequences of bases encode the instructions for synthesizing proteins and regulating various cellular functions. Understanding DNA is crucial for genetics, biotechnology, and many branches of life sciences.