Fallen Enchantress Faction Table
Here's a quick reference guide to the differences between factions:
Faction Special Ability
------------------------------------------------------------------------------------------------
Tarth (Woodland People) Monsters ignore them
Pariden (Sorcerers) Can conjure Magic Outposts (Arcane Monoliths)
Altar (Adventurers) Can train Champions
Gilden (Dwarves) Can train Iron Golem super units
Resoln (Wraiths) Captured Shards become free unit producers
Magnar (Quendar) Can train slaves (units with no upkeep)
Yithril (Trogs) Can train the Juggernaut super unit
Kraxis (Machiavellian People) Can recruit champions from both sides
There's a lot more than that, but those are the biggest differences.