java - Advantage of Thread over Runnable

Possible Duplicate:
Java: “implements Runnable” vs. “extends Thread”

1) Why does Java language provide both Thread and Runnable?
2) What are the advantages of thread over runnable ( why couldnt Java just provide a runnable)
3) Can we make a runnable sleep, give it an id etc?

Answer

1. Thread is a class, and when you say .start() you create a thread of execution which is attached to an Instance of Thread Class. Therun() method of Runnable is called making it execute the task on to the thread of execution, and the start() method returns quickly.

2. Runnable is the task that is assigned to the newly created thread of execution.

3. So without the Thread class, you canNot run your Runnable.