Many water droplets flow down a slope.
A single droplet bounces like a ball, but when many are gathered together, they behave like water. When they break apart, they behave like a ball again.
When people climb the steps up the hill, the droplets near the step receive energy and break apart.

A water molecule on its own is not liquid. In order for water to be a liquid, many water molecules must come together.
Because water molecules act like magnets, they stick to each other, forming a group of water molecules (a water cluster). Water clusters have an extremely short lifespan and are thought to be constantly being created and broken apart. They have a very dynamic structure and because of that, water can change into various forms.

Most living things and objects in this world, through properties that are more than the simple sum of the properties of their parts, appear as a whole.