This presentation was originally presented as part of the 2005 Cornell Nanoscale Facility Fall Workshop, "Modeling the Nanoscale World". An overview of multiple scattering theory and how it relates to electronic structure in materials is provided. In addition, different approaches based on this theory such as the Korringa Kohn Rostoker (KKR) technique and the linear muffin-tin orbital approach (LMTO) are described. Finally an overview of Green's function techniques related to nanoscale transport is also provided.