What differences are there between the Roman Catholic and Eastern Orthodox understanding of the sacrament of marriage?

I read somewhere a couple of years ago that Eastern Orthodox believe marriages contracted on earth, remain in place in heaven (however it is impossible to get married once you arrive in heaven). Whereas Catholics believe that marriages are dissolved at death and everyone in heaven is single. I also heard that Eastern Orthodox allow divorce, but I don't understand how that fits with the "eternal marriage that persists even after death" theology I described above. Is my understanding of Catholic and Orthodox marriages correct? More generally, what is the difference between the Catholic and Orthodox understanding of marriage?