Bruisers are usually top lane(Can be junglers if you're confident and good) who mainly focus on DPS and usually have a semi-decent CC(Crowd control, slows, stuns, taunts, snares etc) kit but they only bruise the enemy unless they're overfed, their job is to lock down the enemy ADC, keep them out of the fight and use their CC on them
AP casters are your nukers, AKA glass cannons, these focus entirely on burst damage which also is primarily focused on the enemy mid laner(AP Caster) or ADC depending on the situation
CC Junglers are tanky junglers who's kit primarily focuses CC, these guys are your peelers, they wrap around their ADC to protect them and make sure the enemy can't touch them with their CC during teamfights
DPS Junglers are your early game nightmares, Lee sin, Udyr, Shaco, Elise and so on. If you're good and you roll DPS junglers, you'll climb ELO like no tomorrow, however, if you suffer early your mid and late will be useless
Feel free to ask anything else, played LoL for like 2 years
DPS - Damage per second
Nuke - burst damage, skill dependent and not auto-attack dependent
CC - Crowd control, slows, snares, stuns and so on
AD - Attack damage
AP - Ability power
ADC - Attack Damage carry, primarily uses auto-attacks but is very squishy