Define what degenerate genetic coding means and why it is advantageous

Degenerate genetic coding means that although there are 64 different codons, there are only 21 amino acids, meaning that there are multiple codons which code for one single amino acid. The advantage for this is that it although there may be a mutation in the codon, if the mutation changes the codon to another codon which codes for the same amino acid, this prevents against the mutation affecting the functionality of the protein.
Essentially, even if there is a mutation in the codon the amino acid sequence may not be altered as multiple codons can code for the same amino acid, preventing a non-functional protein being produced.