what is the diff of MAN and MA?

Here we go again.....

MA comes in a box, has a CD, etc, just like a "regular" game. It has a cost to buy initially, and can be found in a game store or on the website. MA is more singleplayer-oriented, with lots of scenarios, campaigns, and maps that you can play against the AI.

MAN is downloaded off the website and played for free. It only has a couple scenarios, and only one map you can play against the AI. The graphics are a bit better, and the multiplayer is much better, with more frequent patches, a built-in chat room, and an option to issue public challenges. If you pay a small subscription fee, you are able to play multiplayer on all the maps, including the MAN-only maps Crateus and Twin Islands.

To summarize:
MA = big one-time cost, singleplayer-heavy
MAN = small monthly cost, multiplayer-heavy