Can anyone explain the difference between sales revenue and cash...

Can anyone explain the difference between sales revenue and cash receipts?
I thought this was a good result (with the former up 9% on corresponding period). It shouldn't be too long before we're profitable, especially with the new test kits being launched. This should have a snowball effect, with labs are more likely to choose our products, if we have multiple ones on offer.
At any rate, a steadily expanding business is always an good investment providing its reasonably priced.
But then cash receipts are down on the corresponding period, so perhaps I'm missing something (admittedly finance isn't my strong suit - I come from the healthcare vantage point).
That final trade looks strange don't you think? $500 worth of shares just before 4 pm at a much lower price. Looks like weird computer trading to me.