Aimed at the high-end market, the original Europe-only model adds a Zorro II backplane, implemented in programmable logic, to the custom Amiga chipset used in the Amiga 1000. Later improved models have redesigned hardware using the more highly integrated A500 chipset, with the addition of a gate-array called "Buster", which integrates the Zorro subsystem. This also enabled handoff of the system control to a coprocessor slot device, and implemented the full video slot for add-on video devices.
Like the earlier Amiga 1000 and most typical PCs, and unlike the Amiga 500, the A2000 came in a desktop case with a separate keyboard. The case was taller than the A1000 to accommodate expansion cards, two 3.5" and one 5.25" drive bays and, like a traditional PC, it lacks the "keyboard garage" of the Amiga 1000. The A2000 has space for five Zorro II proprietary expansion slots, two 16-bit and two 8-bit ISA slots, a CPU upgrade slot, a video slot, and includes a battery-backed real-time clock.
The A2000 offered graphics capabilities only exceeded among its contemporaries by the Macintosh II, a system which sold for about five times the Amiga's price. Also like the A1000, the A2000 was sold only by specialty computer dealers.
The A2000 was largely succeeded by the Amiga 3000 in 1990.
Source: Wikipedia, "Amiga 2000", available under the CC-BY-SA License.