Asymptomatic coronavirus cases refer to people who do not feel sick despite being infected with the virus. They are capable of spreading the disease to others. They have extremely mild or no symptoms of the infection but test positive for it.
The worry is that asymptomatic cases may go undetected and, as they are carriers, spread the virus to others who may or may not have a mild case like them - most of the time, without even realising they are transmitting it. This adds to concerns that the asymptomatic population may be larger than anyone expected and may play a major role in the rapid spread of coronavirus.
Watch this video to understand how asymptomatic people are spreading COVID-19.