The Stardust Pillar and the Vortex Pillar are two of the four bosses in Terraria known as the Celestial Pillars. Each Pillar represents a different celestial element and has unique characteristics. The Stardust Pillar, representing a glittering celestial remnant known as 'stardust', spawns different minions compared to the Vortex Pillar. The Stardust Pillar is known for spawning enemies like the Stargazer. On the other hand, the Vortex Pillar, representing a deep celestial void known as 'vortex', spawns enemies such as the Vortexian and Storm Diver. Additionally, the weapons gained from defeating each Pillar are different. The Stardust Pillar enables the Stardust Dragon Staff and Stardust Cell Staff, while the Vortex Pillar gives the Phantasm and Vortex Beater.