Adeno-associated virus (AAV) is a small, nonpathogenic virus that has gained attention in the field of gene therapy due to its ability to efficiently infect both dividing and non-dividing cells, as well as its low immunogenicity. However, alternative synonyms for AAV have emerged, such as "helper-dependent AAV" (hdAAV) and "self-complementary AAV" (scAAV). HdAAV is an engineered version of AAV that requires a helper virus for replication, whereas scAAV contains self-complementary DNA strands that result in more efficient gene delivery. Additionally, the term "AAV vector" is often used to describe AAV molecules that have been genetically modified for gene therapy purposes. Despite the varied terminology, AAV and its derivatives remain promising tools for gene therapy.