claro / CLARR-oh / of course
Obviously, the most common word you’ll hear as an affirmative answer in Mexico is going to be si but claro is going to be a close second — it literally translates as “clear” or “clearly,” but you’ll hear it used more like “of course” or “I get what you’re saying.” Honestly I use it most often when I get the gist of what someone is saying, but I know if they keep talking, it will only confuse me again.
Advanced usage: claro que sí — same, only more emphatic.