The PlayStation went through a number of variants during its production run, each accompanied by a change in the part number. From an external perspective, the most notable change was the gradual reduction in the number of external connectors on the unit.
The first conceptions of the PlayStation date back to 1986. Nintendo had been attempting to work with disc technology since the Famicom, but the medium had problems. Its rewritable magnetic nature could be easily erased (thus leading to a lack of durability), and the discs were a copyright infringement danger.
A major feature that distinguishes the PlayStation 3 from its predecessors is its unified online gaming service, the PlayStation Network, which contrasts with Sony's former policy of relying on game developers for online play. Other major features of the console include its robust multimedia capabilities, connectivity with the PlayStation Portable, and its use of a high-definition optical disc format, Blu-ray Disc, as its primary storage medium. The PS3 was also the first Blu-ray 2.0-compliant Blu-ray player on the market.