This document outlines different e-commerce business models: B2B (business to business), B2C (business to consumer), C2C (consumer to consumer), C2B (consumer to business), B2G (business to government), C2G (consumer to government), G2B (government to business), and G2C (government to consumer). It provides brief descriptions of each model and examples. The document also discusses advantages and disadvantages of e-tailing/online retail and defines an e-tailer.