Nintendo Switch’s hybrid console form factor when used without its dock is called handheld mode.
In handheld mode, the console’s main screen, system hardware, and two Joy-Con controllers operate as one portable unit. Players can slide the controllers onto the console’s side rails or use compatible wireless controllers instead. The system’s display and controls are therefore physically connected during play.
Nintendo describes the Switch as having three play modes: TV mode, tabletop mode, and handheld mode. TV mode uses the dock and an external television, while tabletop mode places the console on its kickstand with detached controllers. Handheld mode is the only one of the three in which the console’s screen is held directly by the player.
A common mix-up is treating “portable mode” as the official name. Nintendo’s standard terminology is “handheld mode,” although “portable” accurately describes the experience. The Nintendo Switch Lite supports handheld play but cannot use the dock for TV mode.