Both the AES and the MVS had the same specifications, technically, at least.
Neo Geo MVS (Multi Video System)
The Neo Geo MVS is the large multi-game arcade unit that you'll see at your local pizza place or college arcade. Cabinet owners were a able to exchange the game cartridges that were rather large, and sometimes had no case. Although expensive, you can purchase the MVS PCB (Printed Circuit Board) and use it as a home console.
Neo Geo AES (Advanced Entertainment System)
The Neo Geo AES is what you took home from the store. It was the made-for-home version of the very popular MVS.
-Main Processor: Motorola 68000 (12 MHz) - Different versions of the Neo Geo used different revisions of the 68000. The most common clone is the TMP68HC000, manufactured by Toshiba. All of the revisions run the same and have the same architecture.
-Secondary Processor: Zilog Z80 (4 MHz) - used for audio processing.
-Sound Chip: Yamaha YM2610
-Main Memory: 64KB - Used directly by the 68000.
-Video Memory: 68KB
-Sound Memory: 2KB - Used directly by the Z80
-Resolution: 304x224 (320x240 with 8-pixel borders on each side)
-Color Palette: 65,536 Colors
-Maximum Colors On-Screen: 4,096
-Maximum Sprites On-Screen: 380
-Minimum Sprite Size (In Pixels): 1x2
-Maximum Sprite Size (In Pixels): 16x512
-Maximum Planes (Dimensions - in theory): 3
-Aspect ratio: 4:3
-A/V output: RF, Composite, RGB (with separate 21 pin cable FCG-9).
-Power: 5v DC
-Power Consumption: 5W (1A) Older Systems, 8W (1.6A) Newer Systems.
For more on the Neo Geo Consoles, click here
Thanks to Wikipedia and Neogeo.com for this collection of information.