Dart

Darts are missile weapons, designed to fly such that a sharp, often weighted point will strike first.

Source: Pathfinder d20pfsrd.com

They can be distinguished from javelins by fletching (i.e., feathers on the tail) and a shaft that is shorter and/or more flexible, and from arrows by the fact that they are not of the right length to use with a normal bow.

Ranged Weapons (Simple)
Weapon	Cost	Damage (S)	Damage (M)	Critical	Range Increment	Weight	Type	Special
Dart	5 sp	1d3	1d4	×2	20 ft.	½ lb	Piercing	—

Source: Core Rulebook