HIV is a retrovirus. Retroviruses use their RNA as a template for creating DNA when inside a human host cell. This is how retroviruses multiply.
Knowing that HIV is a retrovirus is important to understanding how HIV treatment works. HIV treatment works by preventing HIV from multiplying. It is able to block multiplication by interrupting different stages of the retrovirus multiplication process.
There are many different classes of antiretroviral therapy. Each class of HIV ART works to fight HIV infection by interrupting various stages of the HIV replication cycle. Some stop or slow down the process of HIV from replicating within the body, while other drugs work by helping the body to fix the damage HIV has done to the immune system. Other drugs work by helping the immune system to become stronger and more effective at warding off illness and infections.
Deciding on a combination of ART is something that an individual usually does in consultation with their doctor or other health care professionals. When deciding upon the most suitable combination for an individual, several factors are considered including but not limited to: viral load, CD4 count, previous treatments and experiences to those treatments, dosages and adherence particulars (how drugs should be taken).