Due to their diversity, viruses are the most numerous biological entities in the world. Work describes the differences between influenza virus and corona virus and their mutations. Influenza viruses are classified into 4 types: A, B, C and D while the known corona viruses are SARS-CoV, MERS-CoV and SARS-CoV-2. Influenza viruses as well as corona viruses are known for their ability to cause epidemics and pandemics. Influenza epidemics occur every year and cause a health, social and economic problems. Large mutations of the influenza virus occur less frequently and cause pandemics that are more dangerous and devastating to humans. Corona viruses are currently in the spotlight due to the SARS-CoV-2 virus that caused the COVID-19 pandemic. The corona virus SARS-CoV caused an epidemic in 2002. while MERS-CoV is still occurring locally. Influenza viruses and corona viruses cause respiratory problems. Influenza virus vaccine is given preventively before the season of the virus to facilitate the immune system's response to the virus. For coronavirus, the vaccine is not yet available, with the exception of SARS-CoV-2 virus, where vaccination is currently in place. SARS CoV-2 virus mutations are a problem, and Alpha, Beta, Gamma and Delta strains have been reported so far. Currently, the most dominant strain is Delta strain, which most often causes COVID-19 disease in young people. Monitoring mutations and the emergence of new variants of the SARS-CoV-2 virus in order to create a comprehensive database on the SARS-CoV-2 genome is extremely important for the quality management of the COVID-19 disease pandemic.