Today the whole world is facing a very difficult time due to corona virus which initially originated in Wuhan city of China. In China an unusual pneumonia was noticed earlier which later recognized as a pandemic. There have been two events in the past wherein crossover of animal corona viruses to humans has resulted in severe disease, one was SARS-CoV and the other was MERS-CoV. The genetic sequence of the COVID19 showed more than 80% similarities to SARS-CoV and 50% to the MERSCoV. Corona viruses are enveloped positive sense single-stranded RNA virus belongs to a large family in which all strains of the family do not have virulent capacity. World Health Organisation has classified COVID-19 as a β CoV of group 2B. Structurally, SARS-CoV-2 has four main structural proteins and several accessory proteins through which it enters into the cell. This virus enters the through ACE2 receptors, which are found on various organs in human body. After entering into one body, it enters to another body via transmission through sneezing, coughing etc. People who have had diabetes, chronic respiratory disease, cardiovascular disease, or even high blood pressure and cancer are at higher risk of coronavirus.