The common name for the influenza virus is simply "the flu." This viral infection primarily affects the respiratory system and is known to cause seasonal epidemics. Symptoms of the flu can range from mild to severe and typically include fever, cough, sore throat, body aches, and fatigue. The influenza virus spreads easily through respiratory droplets when an infected person coughs or sneezes. Vaccines are available to help protect against the most common strains of the flu and are recommended annually, especially for high-risk groups. The flu remains a significant public health concern due to its widespread impact.