This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
The Thread class creates the new thread and then runs your Runnable class in it. If you didn't have the Thread class all your classes that implement Runnable would also have to include code to create and manage a thread.