Electron orbitals are three-dimensional regions around an atomic nucleus where electrons are most likely to be found. These orbitals are characterized by their shape and energy level. The shape of an orbital is determined by its quantum numbers, while the energy level corresponds to its position relative to the nucleus.

There are four types of electron orbitals: s, p, d, and f. The s orbital is spherical and has the simplest shape. It is centered around the nucleus and can accommodate up to 2 electrons. The p orbitals, on the other hand, are dumbbell-shaped and oriented along the x, y, and z axes. Each p orbital can hold up to 6 electrons.

The energy levels of electron orbitals increase as the distance from the nucleus increases. The electrons in the outermost energy levels, known as valence electrons, play a crucial role in determining an atom's chemical properties. Higher energy levels also indicate higher potential energy for the electrons.