Specific nucleotide sequences make up genes. Therefore genes make up codes. This concept can be made simpler with the help of languages. There are different languages spoken by humans. However, all the humans cannot understand all the languages. The words used in a language are like codes. Only the person who knows to speak that language understands those words. Just as words define a language, the genes use codes for communication and sending signals. Hence a genetic code is a linear sequence of nucleotides that specify amino acids. The genetic code is a triplet code. Two popular experiments explaining the theory of triplet code are Francis Brenner experiment and Nirenberg Khorana experiment respectively. Any changes in the sequence of nucleotides lead to different types of mutations, thereby affecting the structure and synthesis of the proteins. There are specific codons for the initiation of protein synthesis, and many such functions. Also, there are two schools of thoughts regarding the universality of the genetic code. Few references suggest the universal nature of the genetic code whereas other concepts contradict this concept.