The human immunodeficiency virus (HIV) belongs to the Retroviridae family and is a virus containing two single-stranded RNA molecules. Its complex structure includes a lipid bilayer envelope, glycoprotein spikes, core proteins, and enzyme systems such as reverse transcriptase, integrase, and protease. HIV primarily targets immune system cells in the human body, such as CD4+ T cells, leading to their destruction and immune dysfunction. It participates in biological responses and signaling pathways through processes such as fusion with host cells, reverse transcription, integration, and virus replication. The genes of HIV exhibit high variability, allowing the virus to evade immune recognition and the effects of antiviral drugs, thereby increasing the complexity and challenges of treatment.