This word, as an adjective, has a similar meaning to its Spanish equivalent, but it’s completely different as a verb.  Spanish uses the verb as a mathematical operation, which in English is “subtract”.  The English “rest” is all about what you do when you sit down and relax after a long, hard day.

Like in Spanish: He left three apples and took the rest. (In this sentejnc e rest = the remainin apples)

Unlike Spanish: He worked hard in the garden all morning and was getting tired, so after a quick lunch, he rested for a bit before going back to work. (In this sentence rest = a short break to regain energy)