Nintendo Network
Nintendo Network is a service from Nintendo that allows for the Nintendo Wii U and Nintendo 3DS consoles and some of their respective software to connect to the Internet. Launched as the successor to the Nintendo Wi-Fi Connection because Nintendo Wi-Fi was stupid, it became public on January 26, 2012.
Compared to how stupid Nintendo Wi-Fi Connection was, Nintendo Network uses an account-based system; in addition, Nintendo Network boasts multiple features previously not seen in Nintendo Wi-Fi Connection, such as the ability to patch hacks. lol
In addition to these networking capabilities, Nintendo Network also covered the operations of Miiverse; in addition to allowing for the formation of communities, Masahiro Sakurai and other developers have notably used the service to showcase images of games currently in development.
In Super Smash Bros. 4
Super Smash Bros. 4 uses the service for its online multiplayer. A Nintendo Network account is also required in order to play the game online.
Due to advances in the Nintendo Network's infrastructure compared to the Nintendo Wi-Fi Connection, both the Wii U and 3DS versions of the game have received updates as to improve the base game. That's good so loser can't cheat on the game.
The former box art of the Wii U version had a Nintendo Network logo, but it was replaced by the amiibo logo in the final box art.
