DNA sequences are the specific order of nucleotides in a DNA molecule. These nucleotides, represented by the letters A (adenine), T (thymine), C (cytosine), and G (guanine), form the genetic code that determines the traits of living organisms. The sequence of these letters is crucial for the proper functioning of cells and the development of an organism. Scientists study DNA sequences to understand genetic information and how it influences characteristics. By analyzing these sequences, researchers can identify genes associated with diseases, track inheritance patterns, and explore evolutionary relationships among different species. This field of study is known as genomics.