How did nominalism differ from Platonic and Aristotelian views of universals?

In Western philosophy, the dispute over universals centers on whether general properties exist independently of the particular objects that exemplify them. Nominalism differs fundamentally from both Platonic and Aristotelian views by denying the existence of universals as real entities.123

• Platonic Realism (universalia ante rem): Plato argued that universals are abstract, eternal, and transcendent forms that exist independently of space, time, and physical particulars. Particular objects are merely imperfect copies that "participate" in these forms.143
• Aristotelian Realism (universalia in re): Aristotle rejected the idea of a separate realm of forms. He maintained that universals are "immanent," existing only as constituents within the particular things themselves. They have no independent existence apart from their instances.143
• Nominalism: Nominalists, such as William of Ockham, assert that reality consists entirely of particulars. They argue that universals are not real things but merely general names or words used to group similar objects. For the nominalist, the application of a general term is explained by the similarities between particulars, rather than by a shared, underlying universal entity.123