DJ controllers are hardware devices that connect to a laptop computer, tablet or phone and allow a DJ to control software on that device with the hardware. A lot of the time when people say they are looking for DJ Decks, they are looking for a DJ Controller to connect to their laptop and control a piece of software, this is what a DJ Controller does. DJ controllers allow DJs to manipulate music files in real time. They typically feature a mixer, jog wheels, and other controls that allow DJs to adjust the tempo, pitch, and other aspects of their music. DJ controllers come in a variety of sizes and configurations, from compact units designed for mobile use to larger consoles that offer more functionality.