Statistics affect more facets of the game than can be listed.
Heres a short run-down of some of what they affect, and definitions.

Strength: How strong you are. Affects the amount you can carry and how 
          Hard you hit.

Intelligence: How smart you are. Affects how fast you learn.

Wisdom: How wise you are (common sense). Affects how many times you can 
	  practice.

Dexterity: How nimble you are. Affects how often you hit and get hit.

Constitution: How healthy you are, in general. Affects hitpoint gain per
              level.

Charisma: How likeable you are. Affects how some monsters treat you 
         (like shopkeepers), and how many pets you can have.

Don't let your statistics get below because bad things can happen.
You can see your current statistics with the [ABILITIES](/help/commands/abilities/) command.

See also: [ABILITIES](/help/commands/abilities/)