Visualizing recursion to solve fibonacci sequence:

					fib(5)
				/		\
			   fib(4)		fib(3)
			/	\		  /       \
		    fib(3)      fib(2)          fib(2)      fib(1)
		/	\	/     \	         /   \
	    fib(2)     fib(1)  fib(0)  fib(1)  fib(0)  fib(1)
           /     \
         fib(1)   fib(0)