Conscript Division - 10,000 - A 'special' unit you can spawn en masse by issuing a draft order. They're free, but also the peasants/militia of this game, though - poorly trained, ill-equipped and with very bad morale to boot. They're really only useful in large numbers, and even then a few units routing will cause a chain reaction, so ironically it might be a bad idea to even field large numbers of these guys. They move at a pace of 1 province/day.
Infantry Division - 8,000 - The workhorse of all armies, a standard infantry unit equipped with small arms and the necessary medical, logistical & command sections. Capable of most tasks on the battlefield. They move at a pace of 1 province/day.
Motorized Infantry Division - 8,000 - An infantry division outfitted with trucks for increased mobility. They can move faster across flat terrain (such as the Russian steppes) than infantry units, but as their trucks are rendered useless in rough terrain like the Amazon rainforest, they will move slower than regular infantry there. They move at a pace of 2 provinces/day on ideal terrain (plains, deserts) and 1 province/2 days on rough terrain (mountains, jungles, swamps).
Mechanized Infantry Division - 8,000/2,000 half-tracks - An infantry division outfitted with armored half-tracked armored personnel carriers armed with MGs, providing them with tremendously improved mobility across all kinds of terrain (except mountains) as well as greater protection against enemy infantry and light armor. They move at a pace of 2 provinces/day on all but mountains, where they move at a pace of 1 province/2 days.
Mountaineer Division - 6,000 - An infantry division specialized for high-altitude and low-temperature operations. They move faster and perform better in mountains than other infantry units. They move at a pace of 1 province/day unless they're in the mountains, where they move at a pace of 2 provinces/day.
Light Infantry Division - 6,000 - An infantry division specialized for operations in rough terrain other than mountains. They move faster and perform better in rough terrain (swamps, jungles, deserts) than other infantry units. They move at a pace of 2 provinces/day, always.
Marine Division - 6,000 - An infantry division specialized for amphibious operations. They will perform better than other units when launching an amphibious assault, especially if they are the ones to lead the attack. They move at a pace of 1 province/day.
Light Armored Division - 4,000/1,000 tanks A division of light tanks, faster than a 'proper' armored division but weaker. Not much else to be said, really. They move at a pace of 3 provinces/day except in mountains, where they move at a pace of 1 province/2 days.
Armored Division - 4,000/1,000 tanks - A division of tanks, any modern general's iron fist on the battlefield. Capable of withstanding tremendous punishment and functioning as both infantry support or independently, punching gaps in enemy lines if deployed in sufficient concentrations and with effective orders. They move at a pace of 2 provinces/day except in mountains, where they move at a pace of 1 province/2 days.
Cavalry Division - 8,000 - A mounted division that moves faster than infantry on a map, and can dismount to fight on foot just as effectively as they do on horseback - this is no longer the day of glorious cavalry charges, after all. They move at a pace of 2 provinces/day except in rough terrain, where they move at a pace of 1 province/day.
Semi-Motorized Cavalry Division - 8,000 - A division outfitted with both horses and trucks, allowing them to outrun most other units except in rough terrain that renders their vehicles useless. They move at a pace of 4 provinces/day except in rough terrain, where they move at a pace of 1 province/2 days.
Artillery Division - 5,000/500 guns - A division outfitted with a large number of heavy artillery pieces. Their fire is much more devastating than that of mere Artillery Brigades, but they are also much slower, and will be annihilated if the enemy can close in on them. They move at a pace of 1 province/2 days.
Rocket Artillery Division - 5,000/500 guns - A division outfitted with a large number of single-rocket launchers. Their fire is much more devastating than that of mere Rocket Artillery Brigades, but they are also much slower, and will be annihilated if the enemy can close in on them. They move at a pace of 1 province/2 days. Russians start with this unlocked, Germans have to research it.
MLRS Division - 5,000/500 guns - A division outfitted with a large number of MLRSes. Their fire is much more devastating than that of mere MLRS Brigades (which are already deadly enough in their own right), but they are also much slower, and will be annihilated if the enemy can close in on them. They move at a pace of 1 province/2 days. Russians start with this unlocked, Germans have to research it.