Comparing the income from operation on the income statement to the cash from operations

Study the financial statement and the statement of cash flows of Barnes and noble with the Link provided. ( Please answer all questions completely)
How does the cash from operating activities differ from the income from operations on the income statement?
What are the major sources for this difference?
Which would you find more valuable in deciding whether to invest in the company or not and why?
http://investing.businessweek.com/research/stocks/financials/financials.asp?ticker=BKS&dataset=cashFlow&period=A&currency=native