A triplet in genetics refers to a sequence of three nucleotides in DNA or RNA that codes for a specific amino acid. These triplets, also known as codons, are essential for the process of protein synthesis, where the genetic code is translated into proteins that perform various functions in living organisms. Each triplet corresponds to one of the 20 amino acids used to build proteins, and the sequence of these triplets determines the structure and function of the resulting protein. The genetic code is universal, meaning that the same triplet can code for the same amino acid across different species, highlighting the shared biological heritage of life on Earth.