print() in Python

Question

print(*objects, sep=' ', end='\n', file=sys.stdout, flush=False)

The stream is forcibly flushed If flush is True. Default value is False
What is meant by "stream is forcibly flushed" and how we cam make value of flush=True and use it ?

Answer 1

~ swim ~ how sys.stdout.flush can be used in the given code ?

Answer 2

But how we know that buffer is used ? by sys.stdout.flush() before flushed by system itself