What causes the disease also known as COVID19 ?

What causes the disease also known as COVID19 ? where did the disease start and what do scientists know about the nature of the disease? were all countries equally affected by the disease and compare and contrast the statistics of the rate of infections and deaths? actions taken by the Saudi government to stop the spread of the disease? outstanding accomplishments of the Saudi government while looking after the human rights of all individuals during the Corona virus pandemic name the preventive measures that can be taken by individuals to protect themselves advice that you would give your family, friends and the community on how to protect themselves during the pandemic.