The development of a use case is visualized through an interaction diagram, which shows how objects send messages to each other within a system.
The realization of a use case, which entails determining what objects collaborate by sending messages to each other to carry out the use case, is done through the development of a interaction diagram. Interaction diagrams are used to visualize the sequence of calls between different objects to achieve a specific usage scenario, or 'use case', within the system. These diagrams come in two forms: sequence diagrams and collaboration diagrams. In the context of object-oriented design, they play a crucial role by showing how different parts of the system interact to perform a particular function or set of functions.