| Kind | Where it copies | Enzyme it brings | How it hides |
|---|---|---|---|
| DNA virus | In the nucleus | Its own DNA polymerase | A free ring of DNA in a nerve cell |
| RNA virus | In the cytoplasm | Its own RNA polymerase | Mostly it does not hide |
| Retrovirus | In the nucleus, after a rewrite | Reverse transcriptase and integrase | Spliced into your own chromosome |