The world of HIV/AIDS, like all other specific topic areas, has its own group of word and abbreviations/acronyms that can confound those not familiar with the topic. There are numerous glossaries out there to help understand all the terms and acronyms. Below are links to two such glossaries.
https://aidsinfo.nih.gov/contentfiles/glossaryhivrelatedterms_english.pdf
http://www.virology.net/ATVHIVGlossary.html