Final answer:
An orbital is the region with the greatest probability for the location of an electron around an atom's nucleus. It is represented by a probability cloud in the electron cloud model, with different orbitals accommodating up to two electrons each.
Step-by-step explanation:
The region that has the greatest probability for the location of an electron is best described as an orbital. An electron orbital is the three-dimensional space around the nucleus of an atom where there is a high likelihood of finding an electron.
The probability of finding an electron at a given distance from the nucleus can be calculated and graphically represented. For example, in the ground state of a hydrogen atom, the radial probability shows a peak at the most probable radius, correlating to the location where the electron is most likely to be found.