Nucleotides are the building blocks of genetic material. They are the basic units of DNA and RNA, which are essential for protein synthesis and replication. Synonyms for nucleotides include nucleosides, nitrogenous bases, purines, and pyrimidines. Nucleosides are composed of a sugar molecule and a nitrogenous base, whereas nucleotides also contain a phosphate group. Purines, which include Adenine and Guanine, have a double-ring structure, while pyrimidines, such as Cytosine, Thymine, and Uracil, have a single-ring structure. In biochemistry, these terms are often used interchangeably, depending on the context and the specific focus of the study. Regardless of the terminology, nucleotides remain a fundamental component of molecular biology.