Coronaviruses are known as envelope RNA viruses that are able to infect and manifest disease in various avian and mammalian species. They have the ability to participate in cross-species transmission as seen in the human coronavirus, Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) in 2002. The most recent emergence of a novel coronavirus, SARS-CoV-2, has entered the world and presents similarities to known human coronaviruses. Mechanisms of viral entry and receptor interactions are key to understanding the process of transmission. Further elaboration will be presented on cross-species transmission and the role of viral proteins in spreading the virus