Yeah. More Star Wars. Get over it.
For those lacking info, I'll provide it. Y'know, the info. Note this is not all-inclusive and, like all generalizations, don't apply to everyone. Physical capabilities have nothing to do with it, so just go with what you will:
Guardians are the muscle of the Jedi. They like to do things hard and fast. They rely more on the lightsaber than the Force, and the Guardian's first priority is to strike the opponent down. They traditionally carry the blade color blue.
Sentinals are more conventional. They use the Force a bit more than Guardians, and therefore have less strength. They're more all-around than anything, well-balanced between attack and defense, and sabers and the Force. They typically hold the yellow blade.
If Guardians are the muscle, Consulars are the brains. They mostly use the Force, so they're not so good with fighting, but are capable of devistating Force techniques. They like to hang back a bit more and provide back-up in case of an emergancy. Their lightsabers tend to be green.
Personally, I like Guardians for their get-it-done attitude.