Humans move by putting one foot in front of the other. Fish swim by moving their tail fin from side to side. Squids have a whole other way of getting where they want to go.
Imagine blowing up a balloon and then letting it go. Air rushes out the back, and the balloon moves in the opposite direction. A similar thing happens with squids. A squid’s body includes a bag made of muscles that fills with water. To move, the squid contracts its muscles, pushing water out and moving itself in the opposite direction. Very much like a balloon.
