ELI5: Explain Like I'm 5

wave collapse

Wave collapse is like a ripple in a pond, but it happens with light or other kinds of energy. When the energy is spread out, it looks like a wave and then when it is squished together it looks like a bunch of tiny dots. It's like if you have a towel that you drop in the water, the water ripples out in a wave but then it collapses in to different patches.