The article states that if you test positive for these tests [RT-rPCR, Antigen Test, or Serological test (Antibody test)] it means you are currently (or, in the case of the Antibody test, have been/had been) infected with SARS-CoV2, but it *doesn't* mean you have COVID-19, which is the disease the virus CAN cause.
So now I'm confused. What is the difference? Can you have an illness from SARS-CoV2 (which is evidently not COVID-19) and if so what are these other illnesses and their symptoms? Part B to this question is: how do these illnesses differ from COVID-19 / and its symptoms? Thank you in advance for your response.