DJ controllers are hardware devices that serve as the interface between a DJ and their music software, providing tactile control over various aspects of music playback and mixing. These controllers typically feature a mixer section with faders, EQ knobs, and a crossfader, along with jog wheels for scratching, beatmatching, and track navigation. Many also include performance pads for triggering samples and effects, transport controls, and dedicated effects sections. DJ controllers come in various forms, including all-in-one units, modular systems, software controllers that rely on a computer, and standalone controllers with built-in audio interfaces. When choosing a controller, DJs consider factors like the number of channels, jog wheel quality, performance pad features, build quality, and software compatibility to find a device that suits their individual needs and DJing style.