Is oxycontin and heroin actually the same thing?

I heard that oxycontin is like the pill for of heroin.
And the only difference is that Oxycontin is released slower over a 12 hour period.
And the reason people get so easily addicted to heroin is cuz it gives you the rush all at one times unlike oxycontin
Is there any other differences between them.

I'm not asking cuz im gonna take it either....
I'm just curious

: http://alcoholdrugstreatment.info/is-oxycontin-and-heroin-actually-the-same-thing