This chapter presents the key aspects of intermodal freight transport as they apply to rail activity. The focus is primarily on rail operations themselves, though with some consideration of the interface between train and terminal. The chapter also focuses on unaccompanied intermodal transport, where the unit load travels by rail on its own, since this forms the overwhelming majority of intermodal rail freight activity. Some consideration is also given to the specific characteristics of accompanied intermodal transport, conveying entire road vehicles accompanied by their drivers. Within the European context, it is important to note that much of the published information, including statistics, relates to the rail element of combined transport, which is not entirely synonymous with intermodal transport. By way of context, prior to considering specific aspects of rail operations, the chapter briefly identifies the key intermodal rail freight markets and the different network design concepts.