is the sequence of codons in DNA or mRNA, which codes for specific amino acids.
works in one direction
the same specific base triplet code for the same amino acid in all living things
non-overlapping
the genetic code is degenerate as there are more possible combinations of triplets than amino acids so some amino acids are coded for by more than one codon
Not all triplets code for amino acids though. For example, some triplets are used to tell the cell when to stop production of a protein - these are called stop codons. They're found at the end of the mRNA.
there are also start signals at the start of the mRNA which tell the cell when to start protein production these are called start codons