Differentiate Hard worker , and  Smart worker.

I just explain the different by some example. If you ask a hard worker to cut down the tree with an axe, he will finish the job in 6 hours by his hard work.

But Smart worker will first take 1 hour to sharpen the axe and he will finish the job in 3 hours.  In simple, smart worker plans well before doing any job when compared to hard worker.