What's the diff. between a 4s, and 4gs Iphone?

Rolando, there is no "iPhone 4gs". Currently apple offers the "iPhone 4" and "iPhone 4S".

The exterior on these two models is mostly the same, just minor difference in silent switch placement and antenna layout.

The hardware differences are that the iPhone 4S has a faster A5 processor and a dual-core graphics chip which can be up to "seven times faster" than the older "iPhone 4". The 4S also has an improved rear camera with higher resolution (1080p video) and better sensor. Both the units have a Retina display, same front facing camera, same 512MB RAM.

On the software side, the 4S exclusively has Siri voice-controlled assistant and display-mirroring via AirPlay. Coming in iOS 6 the 4S will get voice-guided turn by turn directions and FaceTime over cell-network.

There is no such creature as an iPhone 4GS.

the 4s has (over the 4)

1) faster processer

2) more ram (1 gig as opposed to 512 meg in the 4)

3) better rear camera

4) SIRI

5) Retina display

One exists (4S), the other does not (4GS).