The English language terminology used in the classification of swords is imprecise and has varied widely over time. There is no historical dictionary for the universal names, classification, or terminology of swords; a sword was simply a single-edged or double-edged knife.

A sword is an edged, bladed weapon intended for manual cutting or thrusting. Its blade, longer than a knife or dagger, is attached to a hilt and can be straight or curved. A thrusting sword tends to have a straighter blade with a pointed tip. A slashing sword is more likely to be curved and to have a sharpened cutting edge on one or both sides of the blade. Many swords are designed for both thrusting and slashing. The precise definition of a sword varies by historical epoch and geographic region.