The H1N1 Influenza Virus, commonly known as the swine flu, is a strain of the influenza virus that can infect humans. It was first identified in 2009 and is known for causing respiratory illness. Symptoms often include fever, cough, sore throat, body aches, and fatigue. H1N1 spreads through respiratory droplets when an infected person coughs or sneezes. Vaccines are available to help prevent infection, and antiviral medications can reduce the severity of the illness. Public health measures, such as hand hygiene and avoiding close contact with sick individuals, are also important in controlling its spread.