A cradle with a vertical plug (Micro USB or USB Type C) onto which an Android phone or tablet is docked to play music and/or to charge the unit. The dock is built into self-amplified speakers or music boxes, or it is a stand-alone unit that connects via USB to a computer, charger or home theater equipment. Some docks use USB for charging and Bluetooth for playing music.
Starting in 2017, Android devices began to switch from Micro USB to USB Type C connectors. Thus, the dock must match the Android connector type. See Android connector
and Micro USB
Radio and Music Dock
The iHome iC50 is an AM/FM radio, alarm clock and Android music dock. Its sliding plug (top) adjusts to the sockets of an Android phone. (Images courtesy of SDI Technologies Inc., www.ihomeaudio.com)