Simple controller setup
If you wish for a wider range of functions, you can achieve this by integrating a controller into your setup.
Which type of controller (all-in-one, deck controller or others) you choose to integrate is determined by the purpose you use it for and the requirements that go along with this purpose.
Expanded controller setup
The next step in expanding the controller setup is the integration of further sound sources into the signal path. Thus, tracks can also be played back from CD players or turntables. This does not only obviate the need to digitize tracks not already on the hard disc, but it also offers great flexibility (e.g. you can esaily play tracks customers brought along).