"The PlayStation (abbreviated PS, PSone, PSX (which it was known as early in development; not to be confused with the DVR PSX) or PS1) is a 32-bit fifth-generation video game console first released by Sony Computer Entertainment in Japan on December 3, 1994.
The PlayStation was the first of PlayStation series of console and handheld game devices. Successor consoles and upgrades include the Net Yaroze, PS one, PSX, PocketStation, PlayStation 2, PlayStation Portable, and PlayStation 3. The PlayStation was the first "computer entertainment platform" to ship 100 million units, which it had reached 9 years and 6 months after its initial launch.
Source: Wikipedia, "PlayStation_(console)", available under the CC-BY-SA License.