That particular bass has passive electronics. The difference between passive and active electronics is fairly simple. In a passive system, the tone pot works by simply cutting frequencies. Active electronics, by use of a power source(batteries), allow you to also boost frequencies. This gives you greater control over the frequency spectrum coming out of the instrument(tone). Additionally, active electronics can also boost the overall signal to compensate for the signal loss associated with cutting frequencies as in a passive system.
Which sounds better? Totally up to the listener. You may not need the extra control of the active system, or the possible headache of losing your active EQ right before a gig when you don't have a spare 9v battery.