Influenza, commonly known as the flu, is a contagious respiratory illness caused by influenza viruses. It typically presents with symptoms such as fever, cough, sore throat, and body aches. Influenza research focuses on understanding the behavior of the virus, developing vaccines to prevent infection, and studying how the virus evolves and spreads in order to improve prevention and treatment strategies. This research is important for public health, as influenza is a significant global health concern that can lead to severe illness and even death, especially in vulnerable populations such as the elderly and those with underlying medical conditions.