Thief can also use any weapon, but doesn't have as much health, and can't block. Although thief can open any chest. She can use any sword, and cast spells. Disadvantage, swing is slower and has a lot less health. He's faster and has a longer reach at the beginning.
Dwarf is slower but does a lot more damage and can take more hits.
Mage gets a lots more spells, but is almost useless in hand to hand combat. Elf can use any weapon and has some spells to assist. Last char - anyone. Normally another cleric or elf, but basically this is to complement the existing party. Two clerics are handy, as are two fighters, or a thief for added chests.