This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
We're pleased to have you here with us here on the ranch, but there are a few rules that need to be followed, and one is that proper names are required. Please take a look at the JavaRanch Naming Policy and adjust your display name to match it.
In particular, your display name must be a first and a last name separated by a space character, and must not be obviously fictitious. Initials are OK for the first and middle names but not the last. You can change it here
See you have to be specific about what you want to ask. Obvious answer to your question looks like Runnable is interface and Thread is class. If you mean to ask how are they different in terms of working, then following is your answer:
If you extend Thread then your class also becomes a thread and you cannot extend anything else. But if you implement Runnable interface, you have option to extend another Class maybe Animal or Car or whatever and also get the thread benefits by implementing Runnable.
In both the cased you just have to override run(). Call thread.Start and it will go to run method directly.