Answer 1

Omkar Shinde

by extending Thread, each of your threads has a unique object associated with it, whereas implementing Runnable, many threadscan share the same object instance. In the Runnable interface approach, onlyone instance of a class is being created and it has been shared by different threads.

source:
https://stackoverflow.com/questions/541487/implements-runnable-vs-extends-thread-in-java

I hope I was helpful