PSP Go is a handheld console released by Sony in 2009 as a redesign of the original PSP console, however this version of the PSP is the least similar redesign of the original PSP. The main difference is that the console doesn't use UMD (optical discs) as game medium but Flash memory. Games can also be downloaded from Play Store. Other differences are the following:
It's 43% lighter and 56% smaller than the original PSP-1000 and 16% lighter and 35% smaller than the PSP-3000
The rechargeable battery is not removable
The screen slides up and reveal the main controls
USB port was replaced with a proprietary connector
A compatible cable that connects to other devices' USB ports is included with the unit
Bluetooth connectivity was added