RNA viruses are a type of virus that use ribonucleic acid (RNA) as their genetic material. Unlike DNA viruses, which have deoxyribonucleic acid (DNA), RNA viruses can replicate quickly and often mutate, leading to diverse strains. Common examples include the influenza virus, HIV, and the coronavirus. These viruses can infect a wide range of hosts, including animals, plants, and humans. They typically enter host cells and hijack the cellular machinery to produce new virus particles. Due to their rapid mutation rates, RNA viruses can adapt to changing environments, making them challenging to control and treat.