What tern describes a virus?

A virus is often described as an "obligate intracellular parasite" because it can only replicate inside the living cells of a host organism. Unlike living cells, viruses lack the cellular machinery necessary for metabolism and reproduction, relying entirely on their host's cellular processes to propagate. Additionally, viruses can be classified based on their structure, such as enveloped or non-enveloped, and their genetic material, which can be either DNA or RNA.