Melee weapons are STR-based, point-blank-range-only hand weapons. They do not affect your running speed, and do not require aiming time.
Low-Tech Melee Weapons (various)
Direct damage weapons that differ slightly from each other in damage type and character animation, but are basically all similar.
Point-blank-range only "tazer" weapons that cause tiny amounts of energy damage and a minor "stun" effect that makes player characters (only!) run more slowly and aim more slowly.
High damage point-blank-range energy weapons.