Accounting - Cash Flow question?

If I buy some widgets from a supplier on credit - I incur an accounts payable, say for $500.00. When doing a Cash Flow Statement, this is considered an INCREASE in cash flow. What I do not understand is: If I did not spend any cash, my cash position is the same, I still have my $500.00, even though I have the widgets. So how can this be an INCREASE in cash. My cash position should be the same not increased. Or am I confusing cash with Cash Flow ? Please explain......