A second quantized formalism for electrons confined to a plane in a strong perpendicular magnetic field is constructed using vertex operators. They are seen to arise naturally from a holomorphic representation of Laughlin's first quantized wave functions, since they have the unique properties of creating coherent states, satisfying anyonic statistics and factorizing matrix elements. While open string vertex operators are sufficient for representing Laughlin's "ground state" wave functions, it is shown that the vertex operators appearing in the theory of closed strings are needed in order to represent both types of anyonic excitations (quasi-holes and quasi-electrons) which appear in the theory of the fractional quantum Hall effect.