Unified Modeling Language

The UML is a modeling language for specifying, visualizing, constructing, and documenting the artifacts of a system-intensive process.

The UML is not:

The UML is an evolutionary general-purpose, broadly applicable, tool-supported, and industry-standardized modeling language.

The UML enables the capturing, communicating, and leveraging of strategic, tactical, and operational knowledge to facilitate increasing value by increasing quality, reducing costs, and reducing time-to-market while managing risks and being proactive in regard to ever-increasing change and complexity. --cited from Methods & Tools.

More information for UML.