What is interference?

Interference is when waves meet and make new patterns by adding up or canceling each other out.

Imagine you're in a bathtub full of water, and you drop two pebbles into it at the same time. Each pebble makes ripples that spread out across the water. When these waves meet, they can either push together to make bigger waves, or pull apart to make calm spots, like when two ripples cancel each other.

Think of it like playing with shadows on a wall. If you hold up one hand, the shadow is big. Hold up another hand next to it, and sometimes the shadows add together (making a bigger shadow), and sometimes they subtract from each other (making smaller or even no shadow at all).

This same idea happens in real life when light waves meet, like in a prism or on a sunny day when you're walking through water. You can see bright and dark bands, just like the ripples in the bathtub.

So interference is like a fun game that waves play with each other, sometimes making things bigger, sometimes making them smaller, but always creating something new.