The article provides a comprehensive review of the differences in pathogenesis, epidemiology, and clinical features between COVID-19, SARS, and MERS. COVID-19, caused by the 2019 novel coronavirus (SARS-CoV-2), has emerged as a global health concern, spreading rapidly in China and other countries. While it shares some similarities with SARS and MERS in terms of clinical features, COVID-19 has a lower fatality rate (2.3%) compared to SARS (9.5%) and MERS (34.4%). The basic reproductive number (R0) of SARS-CoV-2 is estimated to be higher than that of SARS and MERS, suggesting a higher potential for community spread. The article discusses the viral evolution, receptor binding, and transmissibility of SARS-CoV-2, highlighting the importance of understanding these aspects to develop effective preventive measures. It also reviews the clinical characteristics of COVID-19, noting that the majority of cases present with mild symptoms, and the role of gastrointestinal transmission remains a topic of investigation. The authors conclude that while much is still unknown about COVID-19, the lessons learned from past epidemics can help in managing this new global threat.The article provides a comprehensive review of the differences in pathogenesis, epidemiology, and clinical features between COVID-19, SARS, and MERS. COVID-19, caused by the 2019 novel coronavirus (SARS-CoV-2), has emerged as a global health concern, spreading rapidly in China and other countries. While it shares some similarities with SARS and MERS in terms of clinical features, COVID-19 has a lower fatality rate (2.3%) compared to SARS (9.5%) and MERS (34.4%). The basic reproductive number (R0) of SARS-CoV-2 is estimated to be higher than that of SARS and MERS, suggesting a higher potential for community spread. The article discusses the viral evolution, receptor binding, and transmissibility of SARS-CoV-2, highlighting the importance of understanding these aspects to develop effective preventive measures. It also reviews the clinical characteristics of COVID-19, noting that the majority of cases present with mild symptoms, and the role of gastrointestinal transmission remains a topic of investigation. The authors conclude that while much is still unknown about COVID-19, the lessons learned from past epidemics can help in managing this new global threat.