Pneumonia is an acute respiratory infection that affects the lungs. In this medical condition, the alveoli–small sacs found in the lungs–are filled with pus, which is abnormal and which makes breathing difficult for the individual with pneumonia. There are two known types of pneumonia, they are viral pneumonia and bacterial pneumonia, and each of them has different types of treatments. Pneumonia has been known to be the sole largest killer disease of children. Here, we will look at what the symptoms of this infectious respiratory disease are, amongst other things–causes, transmission, risk factors, and treatment.