In Star Wars: Battlefront, there are 4 basic factions: the Republic (Clones), the CIS (Battle Droids), the Galactic Empire, and the Rebel Alliance. Each faction has the same basic troops, but have special troops unique to the faction, as well as different spawnpoints and vehicles.
The Republic[edit]
The Republic is a nice faction in that their vehicles are very powerful, but they don't have many scouting vehicles, and their vehicles are rather slow. They often have an advantage when going after command points. They are one of two factions (The Empire is the other) to have a mobile command post in the AT-TE.
The CIS[edit]
The CIS is a faction that is somewhat short of health, but can have some tricks up their sleeve. As their heads are either thin or hard to hit, they are hard to snipe. The CIS sniper has two levels of zoom on his rifle, as well as a recon droid that can call in airstrikes.
The Galactic Empire[edit]
The Emipire is heavily based on assault. Their weapons, when used properly, can really deal maximum damage. This is also reflected in their bulky powerhouse vehicles. The other faction to have a mobile command post - The powerful AT-AT.
The Rebel Alliance[edit]
The Rebel Alliance is somewhat of an oddball, as their weapons and vehicles are often unique, but powerful.
The Rebel Alliance overall battlefield approach seems to focus on precision, maneuverability, and speed. As just one example, look at the vehicles for the Battle of Hoth. Imperials: AT-AT, AT-ST. Rebel Alliance: Snowspeeders, tauntauns. Most accurate rifle in the game. Fastest standard troop unit in the game. Some Alliance troops wear camouflage outfits or at least darker uniforms; aiding them in staying undetected on some maps.