Rising accounts-receivable or inventory consumes cash; rising accounts-payable releases it. This line is where growth shows up as a cash cost and where a slowdown temporarily shows up as a cash windfall as inventory is run down.
One-off swings here explain most of the gap between a good cash quarter and a good operating quarter. Look at the components over four quarters rather than one, since seasonality dominates short windows.
Example: Northwind Tools absorbs $21M: receivables up $23M and inventory up $54M, offset by payables up $56M. Without the payables stretch the drain would have been $77M.
Related: working-capital, operating-cash-flow, accounts-receivable, inventory, cash-conversion-cycle