here is the context
In the quarter ended in March, IBM’s revenues rose by 5.1 percent to $19.1 billion, and its gross profits were up by 6.1 percent to $8.25 billion. There were a whole bunch of things that affected the bottom line in the quarter, including a settlement of two audits by the US Internal Revenue Service that gave it back $810 million, but IBM then took $610 million in restructuring charges for unspecified layoffs. The company also took some charges – IBM’s chief financial officer, Jim Cavanaugh, did not say how much – that pushed its overall systems business into the red ink.
Why did US IRS gave 810 to IBM? and what do they mean by saying bottom line?