Direction is everything
The entire difference between "emigrate" and "immigrate" comes down to direction. "Emigrate" means to leave one's country to live elsewhere. "Immigrate" means to enter a new country to live there. The same person does both: they emigrate from one place and immigrate to another.
Think of it as two cameras pointed at the same event. The camera in the home country sees someone emigrating. The camera in the new country sees someone immigrating.
Preposition clues
The prepositions that follow each word are reliable signals. "Emigrate" pairs with "from." "Immigrate" pairs with "to." If you find yourself writing "emigrate to," you probably want "immigrate to." If you are writing "immigrate from," you probably want "emigrate from."
- My grandparents emigrated from Poland in 1948. (left Poland)
- They immigrated to the United States. (entered the US)
- Many skilled workers emigrate from developing economies. (leave those economies)
- Canada actively encourages people to immigrate to its provinces. (enter Canada)
Memory aids
The "e" in "emigrate" stands for "exit." The "i" in "immigrate" stands for "into." This letter-based mnemonic is simple and nearly foolproof.
"Migrate" is the neutral, directionless parent word. Birds migrate. Workers migrate. When you add "e-" (out) or "im-" (in), you specify the direction. If you are uncertain which prefix to use, "migrate" is always safe as a general term.
Related terms
An "emigrant" is a person who has left their country. An "immigrant" is a person who has arrived in a new country. An "expatriate" (or "expat") typically refers to someone living abroad who may or may not have permanently relocated. A "refugee" has been forced to leave their country due to danger, the term is not interchangeable with emigrant or immigrant.