Three question answered about coronaviruses

What is a coronavirus?
"Coronaviruses are a group of related viruses that cause diseases in mammals and birds." "Coronaviruses constitute the subfamily Orthocoronavirinae, in the family Coronaviridae, order Nidovirales, and realm Riboviria. They are enveloped viruses with a positive-sense single-stranded RNA genome and a nucleocapsid of helical symmetry. The genome size of coronaviruses ranges from approximately 27 to 34 kilobases, the largest among known RNA viruses."
Which coronaviruses affect humans?
"Seven strains of human coronaviruses are known:
1) Human coronavirus 229E (HCoV-229E)
2) Human coronavirus OC43 (HCoV-OC43)
3) Severe acute respiratory syndrome coronavirus (SARS-CoV)
4) Human coronavirus NL63 (HCoV-NL63, New Haven coronavirus)
5) Human coronavirus HKU1
6) Middle East respiratory syndrome-related coronavirus (MERS-CoV), previously known as novel coronavirus 2012 and HCoV-EMC
7) Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), previously known as 2019-nCoV or 'novel coronavirus 2019'"
What other names are used for the coronavirus SARS-CoV-2?
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was "previously known by the provisional name 2019 novel coronavirus (2019-nCoV)". "Because the strain was first discovered in Wuhan, China, it has sometimes been referred to as the "Wuhan virus" or "Wuhan coronavirus", although the World Health Organization (WHO) discourages the use of names based upon locations. To avoid confusion with the disease SARS, the WHO sometimes refers to the virus as "the virus responsible for COVID-19" or "the COVID-19 virus" in public health communications. Both the virus and the disease are often called "coronavirus" by the general public, but scientists and most journalists typically use more precise terms." The President of the United States currently uses the term "Chinese virus". The term 'Trump virus' has also been used quite frequently for SARS-CoV-2.

The quotations have all been taken from Wikipedia.