Coronavirus: Get it straight

Corona virus?                

                     COVID-19?  

SARS-CoV-2? 

                                   2019-nCoV?

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Allow me to set it straight for you.

We'll start from the most general and work down to the specific.
(All info below is taken from Wikipedia unless otherwise noted.)

Coronaviruses

are a group of viruses -- including the following -- which can cause respiratory tract infections. These are typically mild, such as the common cold, but are also responsible for SARS, MERS, etc. 

SARS-CoV-2 (Severe acute respiratory syndrome coronavirus 2)

is the strain of Coronavirus responsible for the following disease.
2019-nCoV or nCoV-2019 (novel Coronavirus 2019) was a provisional name for this strain early on. It's "2" because the earlier strain known as "SARS" (SARS-CoV) was the first one.

COVID-19 (Coronavirus disease 2019)

is the disease caused by the strain of virus above. 

2019–20 coronavirus outbreak

is a specific outbreak of the disease above.