Nucleic acid sequences are the specific arrangements of nucleotides in DNA or RNA. These sequences determine the genetic information carried by an organism, influencing traits and functions. Each nucleotide consists of a sugar, a phosphate group, and a nitrogenous base, which can be adenine (A), thymine (T), cytosine (C), or guanine (G) in DNA, and uracil (U) replaces thymine in RNA. The order of these nucleotides forms a code that is read by cellular machinery to produce proteins, which are essential for various biological processes. Understanding nucleic acid sequences is crucial in fields like genetics, molecular biology, and biotechnology, as they provide insights into heredity, evolution, and disease.