DNA, or deoxyribonucleic acid, is the molecule that carries the genetic instructions for all living organisms. Its structure resembles a twisted ladder, known as a double helix. The sides of the ladder are made of sugar and phosphate molecules, while the rungs consist of pairs of nitrogenous bases: adenine pairs with thymine, and cytosine pairs with guanine. This unique arrangement allows DNA to store and transmit genetic information. Each sequence of bases encodes specific traits, guiding the development and functioning of an organism. Understanding DNA structure is crucial for fields like genetics and biotechnology, as it helps scientists explore heredity and genetic engineering.