Why is the genetic code described as being universal?

The genetic code refers to DNA, which is like a blueprint that can be found in all living organisms. DNA is made up of 4 nucletotides: Adenine (A), Thymine (T), Guanine (G) Cytosine (C), whether in a bacteria or in a human, which is what makes it universal. 

The order of the nucleotides A, T , C and G is what makes up genes and determine what they code for. This explain why using the same letters, different combinations or sequences can be found and give rise to an beating heart cell in a human and a feather in a bird.