This chapter aims to offer better understanding of several important topics relating to B2B e-commerce. These issues include B2B electronic data interchange (EDI ), extranet, B2B exchanges or e-marketplaces and international B2B e-commerce. This chapter covers these issues in the B2B environment by providing an overview of e-commerce in the B2B environment according to an organizing framework. The essentials of e-commerce in B2B markets are reviewed. Further, summaries are offered about what is known about EDI , extranet, B2B exchange and international B2B e-commerce. To conclude, implications for researchers and practitioners are outlined.