In chemistry, an orbital is a part of a sublevel of an energy level. Each orbital can hold up to 2 electrons. An orbital is represented by the quantum number m. Orbitals are numbered from -l to l, where l is the quantum number describing the sublevel number. The s sublevel contains one orbital, and the p sublevel contains three orbitals, px, py, and pz. These are the most-used orbitals in chemistry, as they are the most relevant to bonding. In an orbital, the s quantum number refers to spin of the electron, which can either be -1/2 or +1/2.
The s orbital is shaped like a sphere.
The p orbitals are shaped like dumbells:
.-------. .-------.
( X )
'-------' '-------'
Although the p orbitals are shaped like the sign for infinity, it is a good idea to draw them very thin, to avoid confusion with orbitals and hybrid sp orbitals (used in bonding).