Nowadays, the features which characterize intermodal transportation are still not very clear. Even though scientific research has permitted a sector analysis and a theoretic evolution, what inter-modality actually is, still remains to be clearly explained. The aim of the paper is to suggest a discussion on this subject, not as regards terminology, but leading to the identification of those aspects that attribute specificity to the sector. In particular, we want to identify the cargo type and the way the freight is loaded from one modality to another. The analysis will be conducted on the technical, historical and economical components of inter-modality.