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Why is viral DNA called a provirus after reverse transcription?

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Diagram illustrating the process of retrovirus infection and reverse transcription, showing a retrovirus entering a host cell, releasing viral RNA, reverse transcriptase converting RNA to DNA, integration into the host genome, transcription of new viral RNA, assembly of new virions, and budding from the cell. — Reverse transcriptase After a retrovirus infects a cell, an enzyme known as reverse transcriptase converts viral RNA into proviral DNA in the cytoplasm. Proviral DNA then enters the nucleus, where it is incorporated into the host cell's DNA.

Viral DNA is referred to as a provirus because it has been integrated into the genetic material of a host cell.1

In the case of retroviruses, the enzyme reverse transcriptase catalyzes the conversion of the viral RNA genome into DNA. Once this DNA is synthesized, it is inserted into the host cell's genome. By becoming part of the host's genetic material, the viral DNA can replicate along with the host cell's own DNA and be transmitted to subsequent cell generations without immediately causing the destruction (lysis) of the host cell. This integrated, inherited form of the virus is what defines it as a provirus.21