Abstract: Topological phases of matter are exotic states of matter with anyonic excitations such as the fractional quantum Hall (FQH) liquids. FQH liquids are described effectively by Witten's Chern-Simons theories. More general topological phases of matter are described by unitary TQFTs or unitary braided tensor categories. I will explain what are topological phases of matter, the mathematical models for topological phases of matter, their emergence from electrons and classification. If time permits, the application to quantum computing.