An electron hole (often simply called a hole) is the absence or lack of an electron where an electron would normally be in an atom. Because electrons are negative and their charges are balanced by the positive protons, electron holes are positive in charge. Electron holes are not particles, they are classified as quasiparticles. Electron holes are different to positrons, which are the antiparticle to the electron. When electrons change energy levels, they leave an electron hole in their place.