Here's a breakdown:

* DNA Structure: DNA is a double helix composed of two strands of nucleotides. Each nucleotide has three parts: a sugar (deoxyribose), a phosphate group, and a nitrogenous base.

* Nitrogenous Bases: There are four nitrogenous bases in DNA: adenine (A), guanine (G), cytosine (C), and thymine (T). The sequence of these bases along a DNA strand is what constitutes the genetic code.

* Codons: The genetic code is read in groups of three bases called codons. Each codon specifies a particular amino acid, which is the building block of proteins.

So, the specific order of the A, G, C, and T bases within a DNA molecule determines the genetic information that is encoded. This information is then used to create proteins, which carry out a wide variety of functions within the cell and organism.