All-In-One Standalone DJ systems are a newer class of DJ equipment. In fact, there are currently only a small handful of these on the market! These combine the "2 decks and a mixer" layout of a standard DJ controller, but allow you to DJ anywhere without the need for computers or record crates. Instead of lugging your music collection around in the form of either heavy crates of vinyl or a laptop with all of your other important files on it, these systems allow for plug and play loading of media by way of USB thumb drives, SD cards, external, and even internal hard drives. If you wanted to, you could go without a music library entirely and use the system's onboard WiFi to connect a streaming music account(support for different services varies by hardware and software make & model, so make sure to do plenty of research!) and DJ with every track available on your platform of choice!