RNA viruses are a group of viruses that contain RNA as their genetic material instead of DNA. There are several synonyms that are used to describe RNA viruses, including riboviruses, RNA-based viruses, and positive stranded RNA viruses. Riboviruses is a term that specifically refers to RNA viruses that replicate within the cytoplasm of a host cell. RNA-based viruses is a more general term that encompasses both RNA and retroviruses. Positive stranded RNA viruses have RNA that can be directly translated into viral proteins. Understanding the different synonyms for RNA viruses can be helpful in learning about their characteristics and behavior.