What is the difference between our familiar world and the world of molecules?

In the familiar world, people and the objects around them are either at rest or in motion, perform deliberate actions committed for any purpose, in the familiar world everything has its own structure, shape, size.
In the world of molecules, the molecules move all the time in a chaotic order, do not have a strict body shape, they multiply all the time and make up groups of atoms, various lattices (crystal, diamond, atomic, ionic.)