**Explanation:**

HIV (Human Immunodeficiency Virus) is a retrovirus, which means it uses RNA as its genetic material. Let's break down the explanation into the following points:

**1. Retroviruses:**
- Retroviruses are a family of RNA viruses that replicate by reverse transcription, which is the synthesis of DNA from an RNA template.
- They are unique among viruses because they use the enzyme reverse transcriptase to convert their RNA genome into DNA, which can then be integrated into the host cell's genome.

**2. Structure of HIV:**
- HIV is a retrovirus that consists of two copies of single-stranded RNA as its genetic material.
- The RNA genome of HIV is surrounded by a protein coat called the capsid, which is further enclosed in an envelope derived from the host cell membrane.
- The envelope contains viral glycoproteins, including gp120 and gp41, which are involved in the attachment and entry of the virus into host cells.

**3. Replication of HIV:**
- Once HIV enters a host cell, the viral RNA is reverse transcribed into double-stranded DNA by the enzyme reverse transcriptase.
- This viral DNA is then integrated into the host cell's DNA, becoming a permanent part of the host genome. This integration is facilitated by the viral protein integrase.
- The integrated viral DNA is called a provirus, and it can remain latent within the host cell for extended periods.
- When the host cell is activated or undergoes certain stimuli, the provirus can be transcribed into viral RNA, which serves as the template for the production of new viral particles.

**4. Single-stranded RNA (ssRNA) as Genetic Material:**
- HIV has a single-stranded RNA genome, which means it has only one strand of RNA.
- The RNA genome of HIV carries all the necessary genetic information required for the virus to replicate and produce new viral particles.
- This RNA genome is also prone to mutations, which contribute to the high variability and adaptability of HIV.

In conclusion, the genetic material of HIV is single-stranded RNA (ssRNA). This RNA is reverse transcribed into DNA and integrated into the host cell's genome, where it remains as a provirus.