Camouflage is when an animal's colors and patterns help it blend in with the world around it. An animal that blends in is hard to see, even when it is right in front of you. Camouflage is like wearing a costume that matches the background.
Many animals use camouflage to hide from predators, which are animals that want to eat them. A little green frog sitting on a green leaf is very hard for a hungry bird to spot. If the frog cannot be seen, it is much safer.
Hunters use camouflage too. A tiger's orange and black stripes look like the tall grass and shadows of the jungle. The tiger can sneak up close to its prey before the prey ever notices it is there.
Some animals can even change their colors. An arctic hare grows white fur in winter to match the snow, and browner fur in summer to match the dirt and rocks. This way it stays hidden all year long.
Camouflage does not only use color. It can also use shape and pattern. A walking stick insect looks exactly like a thin brown twig, so birds fly right past it without stopping.
Next time you are outside, look very carefully at a tree trunk or a pile of leaves. An animal might be hiding in plain sight, and its camouflage is doing a great job of keeping it safe.