To translate is to put into a different language or interpret. If your brother says, "Gee, Mom, all of my friends have really cool pets, like snakes and stuff," you can translate that statement to mean "I want a snake."
Translate comes from the Latin translates, which means "carry across." The word isn't limited to talking about language. You can translate sales into dollars, or a play into a movie. When used that way, translate means changing something from one form to another.