What does UML do?

Unified Modeling Language (UML) is a standardized modeling language used primarily in software development to create visual representations of various aspects of a system. By using diagrams and other graphical tools, UML helps developers, architects, and stakeholders clearly understand the system's architecture, design, and interactions.

The visual models produced by UML can include class diagrams, use case diagrams, sequence diagrams, and many others. These diagrams capture the relationships between components, the flow of data, and the overall structure of the system, facilitating better communication among team members and aiding in the design process. By visualizing how components interact, UML serves as a blueprint for both development and maintenance throughout the software lifecycle.

In contrast, while other options like listing user requirements, generating source code, or testing functionality are important parts of software development, they do not accurately represent the primary purpose of UML. UML focuses on modeling rather than on the specific tasks or outcomes like requirements gathering, code generation, or testing, which makes it a powerful tool for visualizing and planning software projects.