immigrate:移居入境；To enter and settle in a country or region to which one is not native.
Britain immigrated many colonists to the New World.
英国把大量殖民者移居到了新大陆
emigrate：移居出境,也就是通常说的移民（v）；To leave one country or region to settle in another.
His family emigrated to the U.S.last winter.
他们一家去年冬天移民到美国了.
前两个意思相反,一个是移进,一个是移出