Hello

Please check out the following picture:
http://i55.tinypic.com/35mk6eq.png[^]

I am interested in knowing what the left and right arrows mean precisely.
Does the arrow to the right mean that 'Thread' is dependent on 'Runnable'?
What does the left (bottom) arrow mean?
Someone told me it means 'inherits'.
I'm not sure how that relates to 'implements'.

Thank you for reading.

Regards,