Orbitals are spaces that a electron are most likely to reside in. There are S orbitals that represent a spherical region with only one sign. These electrons are held closer to the nucleus. The P orbitals consist of two signs, a negative and a positive. The P orbitals are further away from the nucleus and has 3 different orientation of direction (X, Y, and Z). There are also d and f orbitals that create more complex molecular orbitals. The kit contains the standard S orbital and the 3 xyz P oribtals. There is also hybridization of s and p orbitals, which are sp, sp2 and sp3 bonding that creates the geometry of tetrahedral, trigonal planar and linear. This is an excellent starting kit that gives a great visualization of basic molecular orbital theory!