StreetPass is a feature present in every Nintendo 3DS system that allows users to exchange data from games & applications that the two own. It is on regardless of whether the 3DS is in sleep mode or not (though the system itself must be on), and automatically acts when another 3DS user walks within the console's range. With it, players can acquire new features in games that they own (even if the game's card is not presently in the 3DS card slot) and obtain the Miis of 3DS users that walk past them.
