API stands for Application Programming Interface, i.e. API is the way for an application to interact with certain system/application/library/etc. For example, there are API's for OS (WinAPI), API's for other applications (like databases) and for specific libraries (for example, image processing), etc.
Acute HIV infection: The first stage of HIV, known as the primary or acute infection, may cause symptoms of fever and skin rash. This is because the virus is multiplying rapidly in the body and infecting immune cells. This phase generally lasts several weeks.
HIV usually causes flu-like symptoms about two to four weeks after infection. This period of time is short and is called acute infection. The immune system brings the infection under control, leading to the latency period. The immune system cannot completely eliminate HIV, but it can control it for a long time.