COVID-19 spreads when a patient breathes out droplets containing the virus. 

When another  person breaths in it will cause the infection. Sometime multiple people get infected. It is rapidly disseminating. 

Sometimes it is transmitted by touching a contaminated surface. People who are closer to or within 6 feet of the infected person are most likely to get the infection. 

Covid is transmitted in multiple ways but breathing the air containing the infected viruses is the single most important way of transmitting. On the other hand these droplets containing viruses land on the eyes, face, mouth especially when they splash or spray by sneezing, coughing etc.