The Chinese company ByteDance owns two versions of basically the same app. In the U.S. we have TikTok, used by an estimated 170 million people, while in China they have Douyin, home to more than 700 million active users. Despite having the same parent company, TikTok and Douyin function as separate worlds. Now, as TikTok simmers in political hot water, the differences between the two apps are under a microscope. To get to the bottom of what sets these sister apps apart, Marketplace’s Lily Jamali spoke with Marketplace’s China correspondent, Jennifer Pak, about why ByteDance has this system in the first place.