The fractional quantum Hall effect (FQHE) has been extensively studied in two-dimensional semiconductor heterostructures in an external magnetic field. It has recently been realized that this is a special case of the more general phenomenon of band topology. Numerical investigations have shown that when a topologically nontrivial band is partially filled with interacting electrons, they form FQH-like ground states. I will show how to understand such states in terms of composite Fermions, which have helped us to understand the conventional FQHE.