Definition of Atomic Orbital
Atomic Orbital is a mathematical function that gives us information about the location of an electron in an atom. It also describes the wave-like nature of the electron. The probability of finding an electron in a region of space around the nucleus of an atom can be calculated as well as determined by this mathematical function.
There are four quantum numbers n, l, ml, ms that characterize the orbitals. The atomic orbitals are known to be the basic building units of the atomic orbital model which gives the idea of the behavior of electrons in matter.