“Zooey”‘s first two differences are not correct, as the aforementioned article explains. Arminianist and Calvinist both believe in “Free Will” and the sufficiency of Christ’ Atoning Death. Calvinist do believe that God has sovereignty in all things, including our salvation, and therefore, God does preordain some to heaven and some to hell. The difference here is that Arminianist believe that out of your goodness you chose to believe in Christ and are rightly rewarded with Christ’ death on the cross. Calvinist believe that you are dead in your sins and would never, in your own accord, chose Christ. God, out of his Grace, does chose to change the will of some (“change their hearts”) so that they desire Christ and freely accept Him.
I would encourage readers to read the aforementioned article. It’s quite good.