CareersCareers are very simply put, the profession that a player might choose. What might seem confusing is the fact that the classes also reflect your profession, however, there is an important difference; you can be a soldier whose taken up as a trader. You don't have to fit into the molds of your classes exactly, the class / career system allows you to customize and expand yourself out a little.
The main reason for the careers is to allow the players to select their faction and guild alignments. If you become a Bounty Hunter, you're given to the Bounty Hunter's Guild. This sets you down the proper path for the life you've selected, but can always be changed in the future if you know how to ask a DM nicely. Your gear is also specifically changed according to your career choices. Below is a list of your available careers and items they begin with, not including what gold / factions they're limited to.
Stormtrooper - Stormtrooper Armor, choice of basic blaster.
Rebel - Rebel Uniform, choice of basic blaster.
Sith - Basic robes, choice of vibrosword or vibroblade.
Jedi - Basic robes, choice of vibrosword or vibroblade.
Gray Jedi - Basic robes, choice of vibrosword or vibroblade.
Civilian - Choice of basic armor, choice of basic blaster, Noble's Cloak.
Spacer - Choice of basic armor, choice of basic blaster, choice of basic vibroweapon.
Mercenary - Choice of +1 armor, choice of basic blaster.
Bounty Hunter - Choice of +1 blaster, choice of basic armor.
Trader - Basic clothing, MK1 Trader's Box, choice of basic blaster.