There are generally 3 types of bassses- all passive, passive pickups w/active preamp, active pickups with active preamp.
In my understanding, passive pickups have stronger magnets than active pickups. Active pickups make up for this fact by putting a battery powered preamp inside the pickup itself. This allows the signal to be of similar strength to passive pickups, but can allow for better dynamics, as the pickups can be raised closer to the strings without affecting the string travel.
Active preamps are simply EQ options you can use to shape your sound from your bass. They can usually be paired with either passive or active pickups.
Most high end Spectors have both active pickups (usually EMG) and active preamps, from what I've seen.
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