Snapchat is a mobile social media platform specializing in photo sharing and instant messaging. The app is known for its “disappearing” public posts and private messages, which are visible for a limited period of time. Notably, Snapchat was the first popular social media application to launch the “Stories” feature in 2013, which allows users to create short, temporarily visible image slideshows. The feature has since been emulated and become a staple across other popular platforms, including Instagram, Facebook, and YouTube. Snapchat is a Casebook value under the "Network Terrain" variable in the code book.