Electrons, which are negatively charged, are attracted to nuclei, which are positively charged, to form atoms. A good pictorial representation of an atom is a cloud of electrons swarming around a tiny nucleus, much the way bees might swarm around a queen who has left her hive. Since atoms make up everything in the world, quarks and leptons are the fundamental building blocks of nature. There are three fundamental forces. The most familiar is gravity, which holds humans and other objects to the Earth, makes the Moon go around the Earth thereby leading to tides, lunar phases and eclipses, and causes the Earth to orbit the Sun thereby leading to seasons.
Gravity is generated by objects with mass.
But because gravity is such a weak force, only bodies of huge mass, such as the Earth and Sun, create a significant effect. In the subatomic world, where protons, neutrons and electrons are extremely light, gravity plays no role. The unification of the electric and magnetic forces was achieved in the 19th century, leading to electromagnetism. The electromagnetic force is the source for all macroscopic forces except those created by gravity. Friction, spring forces, air pressure, the forces in collisions, and so on, originate from the electromagnetic force.