Degeneracy (redundancy) of the genetic code refers to the fact that most amino acids are encoded by more than one codon. There are 64 possible codons (4³) but only 20 amino acids plus 3 stop codons, so on average ~3 codons code for each amino acid. Universality means the code is nearly the same in all organisms; specificity means each codon specifies only one amino acid; non-overlapping means codons are read sequentially without sharing bases.