The coronavirus is a big family of pathogens. Some of them cause mild illnesses like the common cold. Others can cause fatal infections. A coronavirus gets its name from how it looks. Under an electron microscope, these pathogens exhibit spikes that resemble the angles of a crown. There are many coronaviruses that only infect animals. Some evolve in their animal hosts to infect humans. The type that infects humans was first identified in the 1960s. Since then, seven human-infecting types of coronavirus have been identified, including the new Coronavirus also known as COVID-2019.
from Medicinenet.com
