They played CDs
They used CDs for the First one, DVDs for the Second, and Blue Ray for the third
The PlayStation Portable is the only handheld video game console to use an optical disc format, Universal Media Disc (UMD), as its primary storage medium. They will continue to make UMDs for the PSP model. The PS Vita will use a new proprietary flash memory card called "PlayStation Vita card" rather than on Universal Media Discs (UMDs) used by the original PlayStation Portable
No, the original Playstation does not have the capability to read a BluRay disc. You must have the Playstation 3 model for using Blu Ray discs because Playstation 2 also cannot use Blu Ray.
Yes, the PlayStation and PlayStation 1 are the same thing, PlayStation 1 being a retroactive moniker for the original PlayStation. As such, both use the same medium for games, a black CD-ROM.
no they did not see related link
CD's man
Neither The PlayStation nor the PlayStation 2 will read copied discs without the use of a modchip. And there is no way to play PlayStation 2 games on an original PlayStation.
The PlayStation uses 128kB EEPROM Memory Cards.
Games and applications for the PlayStation Vita are not compatible with the PlayStation Portable.
They use Cd's
It is possible to use a PlayStation 2 emulator to play PS2 games on your computer. It is only legal to do if you own an original copy of the game.
It will be in its original state.