As you might guess from their names, the difference between chow mein and lo mein is definitive—but not huge. Both chow mein and lo mein contain vegetables and some sort of meat, and they’re both noodle-based. (“Mein” translates to “noodle” in Chinese, as reflected in the word ramen, which originated with Chinese people who immigrated to Japan.)
What primarily differentiates chow mein from lo mein is how the noodles are cooked—but more on that below.