We have 20 amino acids and 64 codons. And what that basically means is we have these codons that are different but can correspond to the same exact amino acid. And that's exactly what we need by the code being degenerative. So codons consist of three nucleotides. Since there are four types of nucleotides, there are four times four times four, so 64 unique codons. And this is more than the 20 possible amino acids, which means that most amino acids are encoded by several codons.