The assignment model and the transportation model are both optimization tools in Operations Research, but they serve different purposes. The assignment model allocates tasks to agents in a one-to-one relationship, aiming to minimize costs or maximize efficiency for individual assignments, such as assigning workers to jobs. In contrast, the transportation model focuses on efficiently transporting goods from multiple sources to multiple destinations, involving a many-to-many relationship and aiming to minimize transportation costs while meeting supply and demand constraints. Thus, while both models utilize linear programming, they differ in their application focus and structure.