Infection occurs when harmful germs, like bacteria or viruses, enter the body and begin to multiply. These germs can come from various sources, such as contaminated food, water, or even through the air. When they invade, they can cause illness by damaging cells and triggering the body's immune response, which often leads to symptoms like fever, fatigue, and pain. To fight off an infection, the body relies on its immune system, which includes white blood cells and antibodies. Sometimes, doctors may prescribe medications like antibiotics to help eliminate the germs. It's important to practice good hygiene, such as washing hands regularly, to prevent infections from spreading.