What is a double helix where genetic code is found?

Very simply put, a gene is a region of DNA that codes for a protein DNA is composed of 4 different nucleotide bases- guanine, adenine, thymine, and cytosine. A group of three of these is called a codon. A codon codes for a particular amino acid. A protein is composed of a chain of amino acids put together in the codons are in. Therefore the genetic information is the sequence of codons and by extension the sequence of nucleotide bases.