What is pneumonia? what are those medicine can heal pneumonia? how can i prevent or how to prevent pneumonia?

Lung infection: Pneumonia is an infection of lung, usually caused by bacteria or virus but also by fungus, too. Chemicals can cause similar pneumonitis or inflammatory response. Cancers & foreign objects can also block lungs too. Best way to prevent pneumonia is to avoid being coughed/sneezed upon, wash hands frequently, don't smoke, maintain your immune system via diet & exercise. Most important, stop smoking!