Dell XPS 18 (1820, Early 2014) - Manual (Page 6)

6 │ Features
Feature Functionality
7 Headset/speaker port Connect a headphone, a headset
(headphone and microphone
combo), or speakers.
8 USB 3.0 ports (2) Connect peripherals such as
storage devices, printers, and so on.
Provides data transfer speeds up to
5 Gbps.
9 Power-adapter port Connect a power adapter to provide
power to your computer and
charge the battery.
10 Windows button Press to go to the Start screen while
an app is active.
Press for quick access to the most
recently used app or most recently
viewed screen.