Playstation 1 Description:

The original PlayStation, released in December 1995, was the first of the ubiquitous PlayStation series of console and hand-held game devices, which has included successor consoles and upgrades including the Net Yaroze (a special black PlayStation with tools and instructions to program PlayStation games and applications), "PSone" (a smaller version of the original) and the PocketStation (a handheld which enhances PlayStation games and also acts as a memory card).
It was part of the fifth generation of video game consoles, competing against the Sega Saturn and the Nintendo 64.
By March 31, 2005, the PlayStation and PSone had shipped a combined total of 102.49 million units, becoming the first video game console to reach the 100 million mark.

The PS one (also PSone), launched in 2000, is Sony's smaller, redesigned version of its PlayStation video game console.

The PS one is considerably smaller than the original PlayStation (dimensions being 38 mm × 193 mm × 144 mm versus 45 mm × 260 mm × 185 mm). It was released on July 7, 2000, and went on to outsell all other consoles—including Sony's own brand-new PlayStation 2—throughout the remainder of the year. Sony also released a small LCD screen and an adaptor to power the unit for use in cars. The PS one is fully compatible with all PlayStation software. There were four differences between the "PS One" and the original. The first was a cosmetic change to the console. The second was the home menu's Graphical User Interface. The third was an added protection against the use of modchips (by changing the internal layout and making previous-generation modchip devices unusable). The fourth is a lack of the original PlayStation's parallel and serial ports. The serial port allowed multiple consoles to be connected for multiplayer, connecting a console to debugging software, as well as third-party game enhancement devices such as the GameShark.

Released in July 2000, concurrently with its successor the PlayStation 2, the PS one was a considerably smaller, redesigned version of the original PlayStation video game console. Originally launched on July 7, 2000,[11] it went on to outsell all-other consoles including its successor the PlayStation 2 throughout the remainder of the year.[12] It featured two main changes from its predecessor, the first being a cosmetic change to the console and the second being home menu's Graphical User Interface.