Generally the nature of the non-metal oxides is

Non metal oxides are acidic nature but metal oxides are basic in nature.

Metalliod oxides are act as both acidic and basic (Amphoteric).

Ex: ${\text{N}}_{\text{2}}{\text{O}}_{\text{5}}{\text{,\hspace{0.17em}P}}_{\text{2}}{\text{O}}_{\text{5}}$