Heredity can be defined as a biological process that involves the passing on of characters or traits from parents to their offsprings genetically. These traits can be physical for example, height, colour of eyes or mental for example, intelligence.
Codon refers to nucleotide triplets of mRNA that serve to specify the amino acid sequence of proteins. There are total 64 genetic code that specify 20 standard amino acids found in proteins. All codon together make genetic code. For example: AUG is codon that specify amino acid "methionine". AUG codon also serve as initiation codon during initiation of protein synthesis.
