Primitives compare by value, wrappers can compare by identity.
Primitives use '==' for value comparison. Wrappers also support '==', but it checks object identity, not value. Use '.equals()' for value comparison with wrappers. For example, 'Integer a = 1000; Integer b = 1000;', 'a == b' is false, but 'a.equals(b)' is true.