Quick question- Is there only one kind of DNA? Watch
..then you have the various types of RNA.
Genetic codes on earth are composed of either DNA or RNA.
RNA is utilised by most prokaryotes, including many viruses, and is used (comparatively) sparingly by eukaryotes, including humans. The human genome is composed entirely of DNA, with RNA being used in replication, transcription and translation, but not as the actual first principle coding sequence.
DNA stands for deoxyribonucleic acid, and everyone's will have a different structure.
There is only one "kind" of DNA in that all DNA shares a common structure. Diffuse chromatin will condense during the S - stage of a cell cycle to give the Watson - Crick double helical structure that is commonly seen. Each strand is made up of nuclotides; each nucleotide is comprised of a sugar which has bound to it a phosphate group (or 3 in the free state) and a nitrogenous base. These are adenosine, thymine, guanine and cytosine.
So yes, there is only one kind of DNA, but everybody's DNA has a different sequence of these nitrogenous base pairs. If coding, these sequences will eventually translate to different proteins (with sub-units of differing linear amino acid arrangement): if non-coding, the sequence may be reglulatory, and influence gene expression when bound to promotors/inhibitors.