An embedded system is a computer system designed for specific control functions within a larger system, often with real-time computing constraints. 
A scenario defines the Stakeholders, Artifacts, Actions and Perspectives involved in specifying, developing, testing and using Embedded Systems. In particular, A scenario is used here to define tool integration needs. A Scenario is represented using one (or more) UML Sequence Diagram(s).
Use Cases are summarizing and grouping Scenarios, using the UML relations for Use Cases (extends, includes, generalization), and considering States (for example, a state relates to a certain development phase, in which a particular use case is available or not.), Pre- and Post-Conditions, Constraints and Alternate Courses (can the initiating Actor reach his goal using another Scenario?). A set of Use Cases is represented using a UML Use Case Diagram.
The following terms are still under development, and their meaning has not yet been settled by the group. (Once settled, they will appear in the Terminology section above)
An aspect of embedded system development that the ES User Group has identified as of high priority. See ES Group Priority Topic