A player's combat stats consist of:
Health or HP is a player's life bar. If this hits 0, you die, like in most games. This leads to the death screen showing the map and asking if you want to create a new character or respawn with this character.
Attack is the stat that determines how much you hit with melee weapons only.
Mana governs how much mana you have to cast spells with. If you're playing a magic user, this stat is important to boost upon leveling to have more mana to cast spells.
This stat governs how fast you get knocked out from poisons from goblins hitting you, or how long you can last underwater after your breath has run out, and how long you can last when your food and water meters are empty, among other things in-game.