How does the human immune system fight off infections and diseases?

The human immune system is like a superhero team that protects your body from invaders like viruses and bacteria.

Your immune system has different kinds of fighters, like soldiers in an army. When something bad, like a germ, enters your body through your nose or mouth, it’s like an invader attacking your castle.

Your body has skin and mucus, which act like shields. Skin is like a strong wall that stops germs from getting inside you. Mucus in your nose and throat is like sticky glue, it catches germs before they can travel deeper into your body.

If germs slip past the first line, white blood cells jump into action. They're like tiny detectives who find and fight off the invaders. Some of them even have special tools that let them swallow the germs whole!

After a while, your body remembers the germs it has fought before, so next time they come, it can defeat them faster, just like how you get better at playing a game after practicing!