What does a unit represent?

[spartan18a]

What does aunit represent?
Divisions, brigades, regimets, etc?

Are the names given random? e.g. 8th ... etc

[VPaulus]

It's an abstract value.
Look at this thread:
viewtopic.php?t=25930

Also take a look at the sticky "Common Questions":
viewtopic.php?t=27283

[El_Condoro]

Unit size is completely arbitrary and up to the scenario designer. In the original campaign it seemed to be somewhere around division or regiment size, but in the DLCs they seem to be closer to battalion size. In short, there is no direct correlation in the game but in a designed scenario the designer may specify (e.g. my Kharkov MP scenario is pretty much based on battalion sized units).

The names are sequential AFAIK - e.g. the first pionere you buy will be 1st Pionere and then 2nd and so on. If 6 have been bought in a game and 4 destroyed the next will still be 7th et al.