OK, language fans. You may know where the ubiquitous affirmative “OK” originally came from — what it (sort of) stands for — but do you know what roles Martin Van Buren and the telegraph played in its accelerating popularity back in the day? Or why a term built around the letter “K” itself is just a sound marketing strategy? And do you remember when it made it to the moon? Either way, Vox has it covered in this five-minute short covering the somewhat colorful history of “OK.”