Class is the role your character fills on an adventuring team, as represented by training in four skills, called “class skills.” Skills are very broad and cover a lot of different situations, some even overlap.
Mixing divine rituals with arms and armor, clerics stand firm against the forces of evil. Their class skills are empathy, religion, willpower, and wisdom. They begin with one weapon, a suit of light or heavy armor, a shield, a divine implement, a religious book, and a healing kit. Wearing heavy armor doesn't interfere with their spellcasting, so they can fill a lot of different roles depending on the situation. They're also great at healing, with and without magic, so they can help keep their team healthy in and out of combat. Clerics are also sometimes called priests, paladins, druids, inquisitors, templars, oracles, shamans, witchdoctors, or warpriests.
Mages are masters of the arcane arts and a wide variety of academic pursuits. Their class skills are awareness, intelligence, persuasion, and spellcraft. They begin with a weapon, an arcane implement, a lore book, an academic book, and a linguistics book. The versatility of arcane magic allows them to do almost anything the want, as long as they have the skills to pull it off. A mage could throw fireballs one minute, fly the next, and turn all of his allies into fish to swim across a river after that. Mages are also sometimes called wizards, sorcerers, witches, warlocks, enchanters, necromancers, or magi.
Quick and clever, rogues rely on their wits and coordination to overcome obstacles. Their class skills are deception, dexterity, reflexes, and stealth. They begin with two weapons, a suit of light armor, a lockpicking kit, and a trapping kit. They have a lot to offer on and off the battlefield, causing massive amounts of damage with sneaky ambushes and a variety of larcenous skills to help their team overcome obstacles. These crafty combatants are great with ranged or thrown weapons and dual-wielding one-handed melee weapons, while light armor gives them the ability to stand toe-to-toe with most enemies. Rogues are also sometimes called thieves, scouts, rangers, assassins, bards, burglars, ninjas, swashbucklers, or scoundrels.
Trained in the use of martial weapons and heavy armor, warriors are fearsome combatants. Their class skills are fortitude, intimidation, strength, and weaponry. They begin with three weapons, a suit of light or heavy armor, a shield, and a climbing kit. Since they excel with any kind of weapon, most warriors prefer to keep an assortment of them available, using whatever the situation calls for. With a suit of heavy armor and a shield, a warrior can shrug off or completely avoid even the deadliest attacks. Warriors are also sometimes called knights, barbarians, samurai, fighters, soldiers, brawlers, berserkers, or cavaliers.