Playstation

The PlayStation was launched.

Dec 3, 1994

The Playstation was launched in Japan.

The PlayStation 2 was launched

Mar 4, 2000

The PlayStation 2 was launched. 4 years Later they made a slimmer model but technically its the same system.

PSone was launched

Jul 7, 2000

The PSone was launched.
(PSone is a redisign of the PlayStation).

PlayStation Portable was launched

Dec 12, 2004

The PlayStation Portable (PSP (1000)) was launched.

PlayStation 3

Nov 11, 2006

The PlayStation 3 was launched. 3 years later a slimmer version was launched but again was practically the same console.

PSP (2000) and PSP (3000) launched

Aug 30, 2007

The PSP (2000) was launched. (I dont know when the 3000 was launched so I just put it with this).

PSP go lauched

Oct 1, 2009

PSP go launchd

PSP (E1000) was launched

Oct 26, 2011

PSP (E1000) was launched. PSP (E1000) is a budget based psp

ps vita launched

Dec 17, 2011

ps vita launched