Basic

Metal oxides form basic oxides. They react with water to form hydroxides. $N{a}_{2}O+H_{2}O\to 2NaOH$

Acidic

Non-metallic oxides are acidic. They react with water to produce acidic solutions. $C{O}_{}2+H_{2}O\to H_{2}C{O}_3$ When they combine together, they do a Neutralization Reaction, where there is a salt and some water.

Amphoteric oxides

They do not affect pH when added to water. However, they act like acid when put to a base, and act like a base when put against solid. An example would be $A{l}_2{O}_3$.

$A{l}_2{O}_3+6HCl\to 2AlC{l}_3+3H_{2}O$ $A{l}_2{O}_3+2NaOH\to 2NaAl{O}_2+H_{2}O$